What Do We Know About COVID-19?

Issue 5 | Oct 2020 | Half-Yearly | Bangalore

RNI No. KARENG/2018/76650 Rediscovering School Science ISSN: 2582-1636

Page 25 What do we know about COVID-19?

A publication from Azim Premji University Editorial Committee

Chitra Ravi, Editor Radha Gopalan, Editor Ramgopal (RamG) Vallath, Editor Azim Premji University Editorial office, Azim Premji University Azim Premji University PES College of Engineering Campus PES College of Engineering Campus PES College of Engineering Campus Electronics City, Bangalore Electronics City, Bangalore Electronics City, Bangalore Email: [email protected] Email: [email protected] Email: [email protected]

Amol Anandrao Kate Saurav Shome Vijeta Raghuram Azim Premji Foundation Azim Premji Foundation IndiaBioscience, National Centre for #134 Doddakannelli #134 Doddakannelli Biological Sciences, Bangalore Sarjapur Road, Bangalore Sarjapur Road, Bangalore Email: [email protected] Email: [email protected] Email: [email protected] Yasmin Jayathirtha Anand Narayanan Shiv Pandey Azim Premji University Indian Institute of Space Science Azim Premji Foundation PES College of Engineering Campus & Technology, Thiruvananthapuram #134 Doddakannelli Electronics City, Bangalore Email: [email protected] Sarjapur Road, Bangalore Email: [email protected] Email: [email protected] Hridaykant Dewan Azim Premji University Sushil Joshi PES College of Engineering Campus Editorial office, Azim Premji University Electronics City, Bangalore PES College of Engineering Campus Email: [email protected] Electronics City, Bangalore Email: [email protected] Murthy OVSN Azim Premji University Venkata Naga Vinay Suram PES College of Engineering Campus Azim Premji Foundation Electronics City, Bangalore #134 Doddakannelli Email: [email protected] Sarjapur Road, Bangalore Email: [email protected]

Editorial Office The Editors – i wonder..., Azim Premji University, PES College of Engineering Campus, Electronics City, Bangalore 560100 Phone: 080-66144900 | Fax: 080-66144900 | Email: [email protected] | Website: www.azimpremjiuniversity.edu.in A soft copy of this issue can be downloaded from http://azimpremjiuniversity.edu.in/SitePages/resources-iwonder.aspx

About Us i wonder... is a science magazine for school teachers. Our aim is to feature writings that engage teachers (as well as parents, researchers and other interested adults) in a gentle, and hopefully reflective, dialogue about the many dimensions of teaching and lifelong learning of science in class and outside it. We welcome articles that share critical perspectives on science and science education, provide a broader and deeper understanding of foundational concepts (the hows, whys and what nexts), and engage with examples of practice that encourage the learning of science in more experiential and meaningful ways. i wonder... is also a great read for students and science enthusiasts. REDISCOVERING SCHOOL SCIENCE

Image Credits Editorial Front cover: Ultrastructural morphology of Coronaviruses. Credits: Alissa Eckert, MSMI & Dan Welcome to this special issue on the Pandemic. Our aim in this issue is to Higgins, MAMS, on Centers for Disease Control and engage with the many ways in which the pandemic challenges our cognitive Prevention (CDC). URL: https://phil.cdc.gov/Details. bias for certainty. A tendency, as the journalist Marcio Moreira Alves describes aspx?pid=23311. License: Public Domain. it, to "suffer from an absence of doubt". Not just in our ability to access the Back cover: Children in Bangladesh rice field. Credits: physical, social, and psychological necessities for survival. But, also, in our IRRI Photos. URL: https://www.flickr.com/photos/ tendency to seek the certainty of knowledge, of knowing, and of the many ricephotos/8177704814. License: CC-BY-NC-SA. symbols, like words, that we use to capture and share this knowing. This is reflected in our quest and love for answers. The more definitive an answer, the Advisors more certain its wording, the more powerful its hold on us. The neurologist Manoj P. Robert Burton suggests that this “...profound ‘feeling of knowing’ may act as a Rajaram Nityananda reward system that provides the positive feedback necessary for us to learn S Giridhar and to continue wanting to learn...”. Vinod Abraham In contrast, the history of science, and perhaps all human endeavour, indicates Publications Coordinator that our understanding of ourselves and the world we inhabit is more likely to Shantha K be rooted in groundlessness. What we ‘know’ is a function of what questions we ask, what tools we use to query the world, what interpretations we are Publications Associate capable of, as individuals and as a species, at this point in time. All of these are Shahanaz Begum changing in this moment in multiple ways — imperceptibly shaping possibilities that we don't know of yet, and can't imagine exist. As the physician Lewis Illustrations Thomas writes: “Science is founded on uncertainty. Each time we learn Vidya Kamalesh something new and surprising, the astonishment comes with the realization that we were wrong before.” Magazine Design Zinc & Broccoli Seen from this lens, the aim of teaching and learning science may be to [email protected] encourage the ability to more thoughtfully question all finality, all certainty. And, in this questioning, find windows to individual and collective inquiry. Printers Perhaps many of the questions that we ask today have been asked before, or SCPL Bangalore – 560062 seem irrelevant or unanswerable at the moment. But it is in engaging with [email protected] these questions that we build the skill to recognise and ask better questions. As the biochemist and cell biologist Ronald D Vale puts it, “You can't expect to Acknowledgements wake up one morning and run a marathon without training. Similarly, asking Special thanks are due to Sneha Kumari, Azim good questions is a skill that requires practice, training, and mentoring. If a Premji University, Bangalore, for her invaluable child (or adult) is placed in an environment that does not encourage active contribution; Prof. Sandhya Koushika from questioning, then that skill will not become an active habit of mind.” IndSciCov for facilitating the use of their mythbusters; as well as Dr. J. V. Peter from Christian This issue began with questions from science teachers from the Azim Premji Medical College, Vellore, and Satyajit Mayor & Foundation. We hope that in responding to these questions, each author Smita Jain from IndiaBioscience, National Centre for Biological Sciences, Bangalore, for their support provokes you to ask deeper questions. Questions that help explore complex in bringing out this issue. ideas, recognise assumptions, separate what we know from what we don’t, and follow out logical consequences of thought. More importantly, we hope that License this issue offers the opportunity to stay a bit longer with All articles in this magazine are licensed under questions that allow our curious selves to observe a Creative Commons-Attribution-Non Commercial with less fear and more wonder. 4.0 International License Which questions do you choose to stay with longest? Share them with us at [email protected]. Please note: All views and opinions expressed in this issue are that of the authors. Azim Premji University or Azim Premji Foundation bear no Chitra Ravi responsibility for the same. Editor CONTENTS

THE BASICS BOOKLET: COMMON MYTHS ABOUT MICROBES BY SOMDATTA KARAK POSTER: CHAIN OF INFECTION 4 A PRIMER TO INFECTIOUS BY VIJETA RAGHURAM DISEASE EPIDEMIOLOGY SNIPPET: MENTAL HEALTH OF PEOPLE IN ISOLATION KRISHNAPRIYA TAMMA BY ISRC

VIRUSES: THE SMALLEST 9 INFECTIVE BIOLOGICAL ENTITIES : BHOLESHWAR DUBE SNIPPET FASTING, YOGA & SARS-CoV-2 INFECTION BY ISRC

SARS-CoV-2 & THE INCREDIBLE POSTER: SUNO BAT KI BAAT BY INDIAALLIANCE 14 TALE OF THE DYING MONKEYS SNIPPET: CATS, DOGS, HOUSEFLIES & SARS-CoV-2 THEJASWI SHIVANAND BY ISRC

THE INFECTION

WHAT DO WE KNOW 20 ABOUT SARS-CoV-2? SNIPPET: WILL STEAM INHALATION OR NASAL RINSES SHAHID JAMEEL CURE A SARS-CoV-2 INFECTION? BY ISRC

SNIPPETS: ARE PEOPLE FROM NORTHEAST INDIA SPREADING THE SARS-CoV-2 INFECTION? • ARE PEOPLE WHAT DO WE KNOW LIVING AT HIGH ALTITUDES & IN NORTHEAST INDIA 25 ABOUT COVID-19? PROTECTED FROM SARS-CoV-2 INFECTION DUE TO HIGHER UV EXPOSURE? SATYAJIT RATH BY ISRC

SNIPPETS: GOING OUT AND RETURNING HOME • CAN THE 31 COVID-19: SYMPTOMS & SPREAD SARS-CoV-2 INFECTION SPREAD THROUGH THE USE OF N. D. HARI DASS, SHANTALA HARI DASS, AIR CONDITIONING? KAMAL LODAYA & R. V. VANDANA BY ISRC OUR RESPONSE SNIPPETS: RESOURCES ON COVID-19 IMMUNE RESPONSE BY VIJETA RAGHURAM 37 TO COVID-19 • 9 THINGS YOU CAN DO TO MANAGE YOUR COVID-19 SYMPTOMS AT HOME SATYAJIT RATH BY CDC

SARS-CoV-2 INFECTION: SNIPPETS: KALONJI, HOT TEA, GARLIC & COVID-19 43 PROTECTION & PREVENTION • WILL SPRAYING BLEACH ON SOMEONE WHO MIGHT BE ASHA MARY ABRAHAM INFECTED DESTROY SARS-CoV-2? BY ISRC

49 TESTING FOR COVID-19 SNIPPETS: CAN CLAPPING HANDS KILL SARS-CoV-2? YASMIN JAYATHIRTHA • CAN AIR-PURIFIERS PROTECT YOU FROM SARS-CoV-2? BY ISRC

TREATMENT FOR A PANDEMIC: SNIPPETS: COVID-19 mRNA VACCINE • THE SARS-CoV-2 56 AN ONGOING SEARCH VIRUS STAYS INFECTIOUS... • MENTAL HEALTH OF CHILDREN DURING THE COVID-19 OUTBREAK SRIKANTH. K. S BY ISRC

SNIPPET: HOW EFFECTIVE ARE PHYSICAL DISTANCING, 65 MITIGATION OF THE COVID-19 EPIDEMIC WEARING MASKS, & USING EYE PROTECTION IN CURBING T JACOB JOHN SARS-CoV-2 INFECTION? BY ANUSHA KRISHNAN

SNIPPETS: WILL RINSING MY HANDS, MOUTH, & NASAL PASSAGE WITH COCONUT OIL DISSOLVE THE VIRUS ENVELOPE AND PREVENT INFECTION? • MENTAL HEALTH 71 COVID-19 IN RURAL INDIA OF THE ELDERLY DURING THE COVID-19 OUTBREAK • WILL SURANJAN BHATTACHARJI CONSUMING DATURA PREVENT SARS-CoV-2 INFECTION? BY ISRC

LIFE IN TIMES OF COVID-19 SNIPPETS: TALK TO A SCIENTIST 78 BY KARISHMA S KAUSHIK & SNEHAL KADAM G. THANGAVEL, JAYAPRAKASH MULIYIL & ANOOP JAISWAL • SCIENCE CAN BE MORE FUN THAN FUN BY RAGHAVENDRA GADAGKAR THE BASICS

A PRIMER TO INFECTIOUS DISEASE EPIDEMIOLOGY KRISHNAPRIYA TAMMA

Infectious diseases, like ll of us have suffered from (when), as well as the causes, risk factors, the ‘novel’ coronavirus disease at some point in our and modes of transmission (why/how). pandemic, are amongst Alives. Diseases, like the common For example, epidemiologists study how the leading causes of cold and cholera, that spread from one many members of a population suffer person to another are referred to as death across the world. from heart attacks, or how many people infectious diseases. In contrast, heart who live close to a dirty river suffer What are infectious disease, diabetes, and cataract are non- from cholera. They do this by applying diseases? Where do such infectious. Whether infectious or not, principles of epidemiology. diseases come from? we know that any disease can affect The term ‘epidemiology’ comes from How do they spread? many people in a population. But how three Greek words — epi, meaning How do we study them? do we know what causes the disease, on or upon, demos, meaning people, And how do human how often it occurs, how common it is and logos, meaning the study of. It is in a population? Or if it can spread from societies combat or limit a branch of science that studies the one person to another, and who is more their spread? distribution and spread of a disease likely to get the disease? These are the in a population, and applies this kind of questions that epidemiologists understanding towards control of public engage with. health problems. Take the example of the ongoing COVID-19 pandemic (see Who are epidemiologists? Box 1). Epidemiologists have helped You can think of epidemiologists as identify the origins of the disease disease detectives. These detectives (possibly from a wild animal), how it investigate the 5W’s of a disease — the spreads among people (through contact diagnosis or health event (what), the with respiratory droplets), and what person (who), the place (where), the time measures and strategies can help reduce

4 — Rediscovering School Science | Oct 2020 its spread (wearing masks, better hand suffered from infectious diseases. But In fact, a majority (> 60%) of the hygiene, and physical distancing). It is it was only with the invention of the infectious diseases seen in humans this growing body of knowledge that microscope that we were able to peer are believed to have animal origins. enables public health officials to plan into the blood and tissue of infected We may encounter such pathogens adequate and appropriate responses people, and discover that they were on contact with an infected animal, to the pandemic. Understanding caused by certain microorganisms and its blood, or other tissues. Such an epidemiology is particularly relevant parasitic nematodes. encounter leads to disease only if the in preventing the spread of infectious While there are millions of species of pathogen is able to enter and replicate diseases, which are amongst the leading microorganisms, only a handful are within a human host. An infectious causes of premature death across the known to cause infectious diseases in disease that is caused when a pathogen world, especially in poor and developing humans. In fact, many microorganisms ‘jumps’ from an animal host to a human countries. This may explain why are beneficial to us, and are essential population is called a zoonotic disease epidemiology has often been described for a healthy life. Microorganisms or zoonosis, and the event is called a as the science of preventive medicine. (bacteria, fungi, viruses, or protists) zoonotic spillover. For example, the current consensus is that the COVID-19 In the past 30 years, many infectious that cause disease in humans are called human pathogens. Examples infection emerged from a spillover diseases have emerged, leading to a from a wild animal into the human high number of deaths. Unlike non- of diseases they cause include malaria (caused by Plasmodium parasites that population. infectious diseases, infectious diseases are transmitted through mosquitoes), can spread quickly through a population How do infectious diseases spread from rabies (caused by a virus that is due to person-to-person transmission. one human to another? An uninfected transmitted by dog bites), dengue Over the years, studying infectious person can contract an infectious (caused by a virus that is transmitted diseases has allowed us to control or disease by direct contact with an by mosquitoes), and tuberculosis eliminate many diseases (like polio and infected person (touching, hugging), or (caused by Mycobacterium bacteria). smallpox), find cures for others (like for indirect contact with their bodily fluids Similarly, the ongoing COVID-19 bacterial pneumonia), and help prevent such as blood, mucus, or respiratory pandemic is caused by a virus that the spread of many more. Today, as droplets. Such infectious diseases are belongs to the coronavirus family also called contagious diseases. For epidemiologists race to understand (SARS-CoV-2). COVID-19, it is useful to look at where example, respiratory diseases such as such diseases come from, and how we Where do these human pathogens come the common cold and COVID-19 spread can deal with them. from? We encounter many of them through droplets produced when an through our physical environment. infected person speaks, sings, coughs or For example, Vibrio cholerae, the sneezes. But not all infectious diseases Understanding infectious bacteria that causes cholera, is found are contagious. Some are transmitted diseases in contaminated water. Many others through other animals (called vectors). For as long as we know, humans have reside in wild or domesticated animals. For example, people get malaria when

Box 1. Do you know these terms? These terms are common in discussions on the disease in a population at a given chikungunya are caused by an increase in infectious diseases: time. mosquito numbers during the monsoons. • Population: the total number of people • Incidence: the number of new cases of • Pandemic: an epidemic that spreads inhabiting a given region or geographic a disease in a population during a given to many countries or regions versus area. It can also refer to a group of people time period. being limited to a specific area. In the who share a common characteristic, like • Epidemic: a disease that shows rapid and ongoing COVID-19 pandemic, more gender, age, or ethnicity. widespread prevalence (or an increase in than 180 countries have reported cases • Pathogen: an organism that causes number of cases) in an area. This increase of the disease. disease. can occur sporadically or seasonally. For • Endemic disease: a disease whose • Outbreak: a sudden increase in the example, some epidemics are triggered by prevalence is maintained at a baseline number of cases of an infectious disease sporadic changes in disease susceptibility number in the population without in an area. It can occur in a small town, of the host, increased virulence of the any external inputs. In other words, or at the scale of a continent. pathogen, or perhaps the introduction an endemic disease shows a constant • Prevalence: the number of cases of a of the pathogen into a new setting. presence in a given location. For example, disease, or the number of people with In contrast, seasonal epidemics of chikungunya is endemic to India.

— Rediscovering School Science | Oct 2020 5 they are bitten by a female Anopheles up to 2 m (or 6 feet) from the infected keep people inside their homes, and mosquito that has just fed on the person, and can cause disease in those away from public gatherings. A third blood of a person with malaria. Other who come into contact with them. strategy is to encourage research diseases spread through the physical Hence, spread of COVID-19 can be into drug development to treat the environment. For example, cholera controlled by minimizing the possibility infection. These drugs could include spreads through the consumption of people making contact with these antibiotics for bacterial infections, of water contaminated with Vibrio droplets (see Fig. 1). One strategy that or antivirals to treat viral infections. cholerae. Also, the prevalence of public health officials rely on is to Most containment measures during infectious diseases can vary over time, identify people who are (or are likely to this pandemic are aimed at slowing across seasons, and across regions. be) infected, as well as those they may the spread of infection enough to give have come into contact with, as quickly a head-start to the public healthcare Controlling the spread of as possible. These people are encouraged system. This is needed to identify infectious diseases to physically isolate themselves at home clinical symptoms of the infection, (if mild), or in a hospital to reduce the and develop corresponding treatment An understanding of the epidemiology risk of spreading the infection to others. and management regimens. In the of an infectious disease allows public A second strategy is to encourage meanwhile, the medical research health officials to plan a variety of people to use masks to cover their nose community has continued working on strategies to control its spread. In an and mouth, maintain physical distance, testing and developing existing and ongoing pandemic, many of these and avoid crowded areas. Many new medicines for use against this strategies will often need to be used at countries have relied on lockdowns to infection. the same time. When a new infectious disease emerges, the first priority of public health efforts COVID-19 is transmitted via respiratory droplets that can infect a person is to prevent its incidence. Strategies when they enter through the nose and mouth. to do this are based on a recognition of the causes of the disease, and the origins of the pathogen causing it. One strategy involves the control Enters nose of conditions favouring the survival and mouth and multiplication of the pathogen outside its human hosts. For example, minimizing the chances of mixing Wearing a mask reduces the number of droplets released by an infected person. sewage and other effluents with drinking water can help prevent cholera. Another strategy is to facilitate a change in patterns of human behaviour. For example, encouraging the use of mosquito nets in places that show a high burden of mosquito-borne diseases such as malaria and dengue can help reduce their incidence. A third Wearing a mask and maintaining 2 m distance reduces both the number of strategy is to provide vaccination, if droplets released by an infected person, and an uninfected person's chances of inhaling these droplets. available, to susceptible populations. Vaccines help prevent the incidence of a disease by strengthening our immune response to the pathogen causing it. The next priority of public health officials is to limit person-to-person 2 m distance spread of the disease in a population. Strategies to do this are based on an understanding of all the ways in which Fig. 1. Droplets released by an infected person can lead to spread of respiratory diseases the infectious agent can spread among like COVID-19. Wearing a mask, and maintaining physical distance limits the spread of the people. For example, COVID-19 spreads droplets, thus reducing risk. via respiratory droplets that can travel Credits: Krishnapriya Tamma. License: CC-BY-NC.

6 — Rediscovering School Science | Oct 2020 Parting thoughts Understanding the origin and spread how a disease spreads in a population. biologists, medical experts, and social of infectious diseases is an important Therefore, the study and application scientists — as well as the cooperation part of public health efforts. Apart of infectious disease epidemiology and collective efforts of communities from the biology of the pathogen, requires the collaboration of experts at risk. human behaviour can also determine from different fields — epidemiologists,

Key takeaways

• Epidemiology is a branch of science that studies the distribution, causes, and possible control of (infectious and non-infectious) diseases in a population. • Infectious diseases are caused by a variety of microorganisms (certain species of bacteria, viruses, fungi, and protists) and parasitic nematodes. • Humans come in contact with a new disease-causing organism through their physical (air, water, soil) or biotic (wild or domesticated animals) environment. • Infectious diseases can spread from one human to another through direct or indirect contact, animal vectors, or the physical environment. • Depending on their causes, origins, and modes of transmission, public health efforts use different strategies to prevent the incidence of an infectious disease, and control its spread. • The study and effective use of infectious disease epidemiology requires the collaboration of experts from different fields, as well as the cooperation and collective efforts of communities at risk.

Note: Source of the image used in the background of the article title: https://www.futurelearn.com/courses/diabetic-eye-disease/0/steps/47630. Credits: London School of Hygiene & Tropical Medicine, FutureLearn. License: CC-BY-NC-SA.

Krishnapriya Tamma works as an Assistant Professor at Azim Premji University, Bangalore. Her PhD from the National Centre for Biological Sciences (NCBS), Bangalore, focused on investigating biogeographic patterns of small mammals in the Himalayas. She is interested in large-scale patterns of species distributions, and the factors that influence them. Her current work investigates the recovery and resilience of tropical forests. She can be contacted at [email protected].

— Rediscovering School Science | Oct 2020 7 SNIPPETS

MENTAL HEALTH OF PEOPLE IN ISOLATION

There have been several efforts to examine the routine, coupled with a lack of activity, can contribute to psychological experiences of patients undergoing anger, resentment, and frustration in the person. Individuals quarantine/self-isolation over the years, not only in the in isolation/quarantine are likely to experience boredom, context of COVID-19. Some mental health concerns which can lead to feelings of emptiness and helplessness. It found to be prevalent among such people are depressed is also important to consider the person’s limited access to mood, emotional disturbances, increased levels of stress, resources that normally help them cope with adversity. For irritability, insomnia, post-traumatic stress symptoms, example, in hospital settings, one’s access to a variety of anger, and emotional exhaustion. Of these, depressed mood food, internet connectivity, entertainment devices, books, and irritability stand out as especially common concerns. and clothes might limit self-care. Others include frustration due to uncertainty and lack of Worry and concern can be unpleasant, but are information about health and recovery, and the possibility understandable experiences at this time. It is important of infecting others. to attend to what one can do in terms of self-care. The typical duration of quarantine for COVID-19 is 14 days, Focussing on the present, and on actions that one assuming that the person tests negative for the virus at can control might help. Find ways to stay connected the end of quarantine. The uncertainty associated with the with others. Establish a daily routine and limit the test results can cause a person to experience higher levels consumption of news regarding COVID-19. Try to of stress. Quarantine conditions can also apply to people incorporate some physical movement through yoga, who are not currently showing symptoms of COVID-19, but exercises, stretching, and squats — all of which can be are at risk of being infected with the virus. In such people, done at home. Fight boredom through resources available worry about the possibility of carrying the infection can be at home, or trying out your hobbies. Ultimately, being a source of stress. A lack of information on the rationale for compassionate to oneself, and finding ways to both offer quarantine can add to uncertainty, and cause one to feel and receive help from others can help manage loneliness a lack of control over the situation. Changes in one’s usual as a result of being in quarantine/isolation.

Notes: 1. This response was first published on the Indian Scientists’ Response to CoViD-19 (ISRC) website. 2. Source of the image used in the background of the article title: https://pixabay.com/photos/stay-at-home-staying-home-5094617/. Credits: soumen82hazra, Pixabay. License: CC-0.

Indian Scientists’ Response to CoViD-19 (ISRC) is a group of more than 500 Indian scientists, engineers, technologists, doctors, public health researchers, science communicators, journalists and students who voluntarily came together in response to the COVID-19 pandemic. This group can be contacted at [email protected].

8 — Rediscovering School Science | Oct 2020 Azim Premji University

THE BASICS

VIRUSES: THE SMALLEST INFECTIVE BIOLOGICAL ENTITIES BHOLESHWAR DUBE

What are viruses? How oday, the world faces an mosaic disease in tobacco plants in 1883 were they discovered? unprecedented threat from a played an important role in the discovery What do we know of Tvirus. But this is not the first viral of viruses (see Fig. 1). Mayer showed infection that we know of. Numerous their structure? How that this disease could be transmitted diseases in plants and animals are caused by inoculating a healthy tobacco plant do they replicate and by viruses. The common cold, dengue, with the sap of an infected one. In multiply? Where do they smallpox, measles, rabies, polio, hepatitis, 1892, Russian biologist Dmitri Ivanovsky come from? Do we know some kind of cancers, and AIDS are passed the sap from infected tobacco of any viruses that are examples of the many viral diseases that plants through special porcelain filters. beneficial to us? have shaped human history. The pore size of these filters was small enough to prevent bacterial cells from Nature and structure passing through. Ivanovsky found The existence and structure of viruses that the sap remained infective even remained a mystery for a long time. Till after all the bacteria from it had been the early 19th century, bacteria were filtered out. Around the same time, believed to be the smallest disease- the Dutch microbiologist Martinus causing organisms (or pathogens). Beijerinck suggested that the filtrate in Simple experiments conducted by the Ivanovsky’s experiment had an infectious German scientist Adolf Mayer on the agent smaller than bacteria. He called

— Rediscovering School Science | Oct 2020 9 genetic material enclosed in a protein A glycoprotein in the phospholipid coat’. Its genetic material is in the form envelope of the virus gets attached of one or two strands of DNA or RNA. to a matching receptor on the host This is used to identify and classify cell membrane. The virion (consisting viruses. No known virus particle contains of the outer capsid and the inner both kinds of nucleic acids. The protein core of nucleic acid) enters the host coat, or capsid, of a virus provides cell through endocytosis, or fusion of structure and protection to its genome. the virus envelope with the host cell Some viruses, like the ones causing the membrane. Enzymes from the host common cold, influenza, or COVID-19 in cell’s cytoplasm dissolve the capsid, humans, have a phospholipid envelope setting the virus RNA free. The virus Fig. 1. Studies by multiple scientists on over their protein coat. This envelope is the tobacco mosaic disease played an RNA replicates and directs the synthesis important role in the discovery of the derived from the host cell membrane, of proteins for the virus capsid. In tobacco mosaic virus (TMV) as well as but can also contain virus proteins and short, the virus genome takes control viruses in general. This infection causes a glycoproteins. The protein capsid and of the genetic and protein synthesis mosaic-like mottling and discolouration of the phospholipid envelope (if present) machinery of the host cell. Paralysed leaves of tobacco plants. help the virus infect its host (see Fig. 2). in terms of its own physiological and Credits: R.J. Reynolds, USDA Forest Service, Wikimedia Commons. URL: https://commons. genetic functions, the host cell ceases wikimedia.org/wiki/File:Tobacco_mosaic_virus_ Replication and to exist, releasing numerous newly symptoms_tobacco.jpg. License: CC-BY. multiplication assembled virus particles. Each of these Outside a host, viruses can be found virus particles can invade another cell in air, water, soil, and various surfaces or infect a new host (see Fig. 3). Often, this infectious agent “contagium as biologically inactive particles. On a virion may enter its host, but remain vivum fluidum”, meaning a contagious contact with a potential host cell, in hiding. The virus genome establishes poisonous fluid. The American scientist the virus starts behaving like a ‘living’ a relationship of co-existence with the Wendell Stanley crystallized the tobacco entity capable of replication and host genome. The host develops disease mosaic virus in 1935, demonstrating its multiplication. This can be seen, for symptoms, and releases virus particles particulate nature. example, when the enveloped RNA only when this relationship breaks down Stanley’s achievement, for which he viruses that cause the common cold (usually because of lowered immunity received the Nobel Prize in Chemistry in in humans come in contact with any in the host). This is seen, for example, in 1946, started an endless debate about cell lining the human respiratory tract. Herpes simplex infections in humans. the nature of viruses. At the heart of this debate is the question — should viruses be classified among living organisms or non-living matter? These tiny entities require a living cell, called a host, to multiply. Like living organisms, they have genetic material, the capacity to replicate and multiply, as well as cause disease in their animal, plant and bacterial hosts. Unlike living organisms, viruses do not respire, do not have their own metabolic machinery, do not grow, and can be crystallized. On the whole, they are among the most mysterious biological entities that we know of. Viruses are so small that they cannot be seen with optical microscopes, let Fig. 2. The structure of a virus particle is simple. Its core consists of genetic material in the alone the naked eye. The largest known form of one or two strands of DNA or RNA. The bacteriophage (a virus that parasitizes bacteria) virus is only about 750 nm (1 nm = 10–6 to the left has double-stranded DNA, while the influenza virus to the right has double-stranded RNA. This core is enclosed within a protein shell called the capsid. The capsid in some viruses, mm or a millionth of a mm) in size. The like the influenza virus, is covered by a phospholipid envelope. structure of a virus is simple, and can be Credits: Adapted from an image by Dr. Tim Sandle, Pharmaceutical Microbiology. URL: https://www.bbc. thought of as an ‘infective particle with co.uk/staticarchive/2effc5b6f748963d346ae11763b12f9ef34ba8af.jpg.

10 — Rediscovering School Science | Oct 2020 Origin and evolution instances of ‘genetic co-mingling’ sequences of a few structural proteins, suggest that viruses have a long history. and become capable of attaching to Where do viruses come from? How More recent studies reveal similarities and infecting undamaged cells. In have they evolved into the forms that between the genomes of viruses that contrast, the ‘regressive’ hypothesis we know of today? Scientists attempt infect two different host species, suggests that the viruses may have to answer these questions in two ways. suggesting that a common ancestor of originated from more complex, free- They look for genetic material, chemical the two hosts may have been infected living organisms. Through a regressive signatures, or symptoms typical of with a common ancestor of the virus. or reductive process, these organisms virus infections in soil and fossils; and In addition, historical examples of may have lost most of their genetic compare the genetic sequences of parasitism, and the fact that all living information over time and adopted a different viruses to estimate how closely organisms today are infected by at parasitic approach to replication instead. they are related. least one type of virus suggest that Both these theories are based on the These studies offer some circumstantial viruses may have been our ‘evolutionary assumption that viruses could not have evidence that the first viruses may companions’ through time. existed as living entities before other have evolved around the same time But what is the nature of this living cells came into being. But what as life evolved on earth. Although relationship? Should one think of if the origin of viruses predates that their categorization as living beings is viruses as the most complex molecular of cells? According to the ‘virus-first’ debated, the genetic code of a virus, like compositions of nature, or as the hypothesis, viruses may have originated that of all other organisms, is written simplest forms of life? While there is as self-replicating units in a pre-cellular in the universal language of nucleic much debate among virologists, three world. Over time, these units may have acids. This suggests a close evolutionary main hypotheses have been articulated. evolved into the more organized and relationship between viruses and the According to the ‘progressive’ complex forms that we see today. Which ‘living’ world. Interestingly, some studies hypothesis, viruses may have originated of these is most plausible? At present, suggest that the genomes of viruses as simple, naked, mobile fragments studies suggest the likelihood that infecting a host have more in common of cellular nucleic acid, which gained viruses may have originated at multiple with the host genome than with viruses the capacity to enter and exit cells times, through multiple independent infecting a different host. Others show with damaged membranes. Through a mechanisms. This is not all. Since viruses the presence of viral DNA sequences in progressive process, these fragments evolve quite rapidly, novel species (like the genetic code of their hosts. Such may have acquired the genetic SARS-CoV-2) are being discovered quite

Fig. 3. A simplified diagram of the replication cycle of an enveloped RNA virus. Replication of this enveloped virus involves the (a) attachment of the envelope to the host cell membrane, (b) entry by endocytosis of the virion, (c) uncoating of the virus RNA by cellular enzymes, (d) virus RNA synthesis, (e) virus protein synthesis, (f) assembly of virus particles, and (g) release of virus particles with envelopes. Note that the genome of this virus is in the form of a minus strand of RNA (-RNA). This strand can act as a template for the synthesis of many complementary strands, called plus strands of RNA (+RNA). The +RNA is like an mRNA molecule, and can be immediately translated into proteins. It can also act as a template for the synthesis of more -RNA strands for the next generation of viruses. Credits: GrahamColm, Wikimedia Commons. URL: https://commons. wikimedia.org/wiki/File:HepC_replication. png. License: CC-BY.

— Rediscovering School Science | Oct 2020 11 frequently. But tracing their origin, and protective viruses. The bacteriophages and Salmonella sp. Some viruses protect understanding their evolution continues (viruses that are parasitic on bacteria) us from other pathogenic viruses. For to remain both a challenge and a source found on the mucous membranes of our example, the dormant form of Herpes of enduring curiosity. digestive, respiratory, and reproductive simplex virus helps natural killer (NK) systems are excellent examples of cells in identifying cancer cells, and Parting thoughts this. Recent research shows that cells infected with other viruses. Not Viruses are often seen only as disease these bacteriophages protect us from only do viruses have an important causing microbes, but they interact with pathogenic bacteria. Many of these role in microbiology and genetics, humans in many complex and diverse phages are used in the treatment of the treatment of viral and bacterial ways. Just as our body hosts bacteria dysentery, sepsis, skin infections, as well infections with bacteriophages is now that help in digestion, it also hosts many as infection by Staphylococcus aureus an emerging field in medicine.

Key takeaways

• Viruses are the smallest biological entities, even smaller than bacteria. They cannot be visualized under an optical microscope. • Viruses contain either DNA or RNA as their genetic material. No known virus contains both types of nucleic acids. • The debate on whether viruses should be classified as living beings or non-living particles is ongoing. • Once inside a host cell, the virus genome takes control of the genetic and protein synthesis machinery of the host cell to replicate and multiply. • Outside a host, viruses can be found in air, water, soil, and various surfaces as biologically inactive particles. • Current evidence indicates that the first viruses may have evolved around the same time as life evolved on earth, and that a close evolutionary relationship exists between viruses and the ‘living’ world. • Three hypotheses — progressive, regressive, and virus-first — have been offered to explain the origin of viruses. Available evidence suggests that viruses may have evolved many times by many independent mechanisms. • While viruses evolve quite rapidly and novel species are discovered frequently, tracing their origin, and understanding their evolution continues to remain a challenge. • Viruses interact with us in complex and diverse ways. Some cause disease, while others protect us from diseases caused by pathogenic bacteria and other viruses.

Note: Source of the image used in the background of the article title: https://www.freepik.com/free-vector/close-up-isolated-object-different-types- virus_7431841.htm. Credits: user brgfx, Freepik.com. License: CC-BY.

Bholeshwar Dube obtained a PhD from Barkatullah Vishwavidyalaya, Bhopal, and retired as a Professor and Head of the Botany Department at Mata Jijabai Postgraduate College, Indore, Madhya Pradesh. He is actively engaged in teacher education programmes and keenly interested in writing popular science articles. He can be contacted at [email protected].

12 — Rediscovering School Science | Oct 2020 SNIPPETS

FASTING, YOGA & SARS-CoV-2 INFECTION

Can fasting help reduce the chances of getting infected by SARS-CoV-2. Thus, fasting is, by no catching the SARS-CoV-2 infection? means, a preventive measure for SARS-CoV-2. What is helpful is to stay healthy by eating a balanced diet, ensure While many studies have shown that nutrition and immunity physical distancing, and maintain personal hygiene. are linked to each other, some studies suggest that fasting “resets” the immune system. However, there is no evidence to suggest that fasting reduces the chances of getting Will practicing yoga protect us against infected. SARS-CoV-2 is known to spread mainly through SARS-CoV-2 infection? the respiratory droplets that an infected person releases The practice of yoga is believed to reduce stress, lead when they cough or sneeze. It is just as likely to infect a to better overall fitness, and a sense of well-being. The person who is fasting as it is to infect a person who is not. healthier a person is in general, the higher their chance of While fasting can mean different things to different recovery from any disease. However, none of these factors people, it may cause stress, low blood sugar levels, guarantee immunity against COVID-19 specifically. Also, headache, dizziness, hyperacidity, fatigue, and weakened there is no evidence to support the claim that yoga can immunity, all of which may increase a person’s risk of prevent and cure SARS-CoV-2 infection.

Notes: 1. These responses were first published on the Indian Scientists’ Response to CoViD-19 (ISRC) website. 2. Source of the image used in the background of the article title: https://pixabay.com/illustrations/meditation-spiritual-yoga-1384758/. Credits: Activedia, Pixabay. License: CC-0.

— Rediscovering School Science | Oct 2020 13 THE BASICS

SARS-CoV-2 & THE INCREDIBLE TALE OF THE DYING MONKEYS THEJASWI SHIVANAND

Where did the SARS-CoV-2 he story of the coronavirus suddenly, out of nowhere, fully equipped come from? Did it appear causing the COVID-19 pandemic, to infect human beings? technically called SARS-CoV-2, suddenly, out of nowhere, T Let us, for a moment, assume this to be is yet to be fully unravelled. While fully equipped to infect us? true. If so, the virus would need to exist our immediate impetus is to discover in a form that allowed it to pass the Or is it a virus from a bat ways to treat and prevent the infection various barriers that the human body or pangolin that suddenly using drugs and vaccines, the pandemic offers to infection. This includes hairs jumped species to infect has also raised many other questions. in the nasal passage and mucus in the us? How common is it for Where did this virus come from? Are upper respiratory tract, both of which there other unknown viruses and a microbe to jump host could trap the virus before it reached bacteria lurking somewhere, waiting species? And why would a its most common site of infection — the to infect us? Where are they lurking, microbe make such a jump? respiratory epithelium tissue, deep within and why are they not known to us yet? our lungs.2 Once it reaches this tissue, the Why, and how, do new diseases strike virus would need to recognise and enter human beings? Do all new diseases a cell with precision. Once inside a cell, have the potential to reach pandemic the virus would need to reproduce, make proportions? These questions are, today, copies of itself, and be released from the of vital interest to everyone — from infected cell. It would also need to be epidemiologists (who study patterns of expelled from our lungs in a sneeze or disease spread) to the common man. coughing bout, and remain active long enough to infect another host. How did Did the virus know? the virus figure out that being suspended The earliest reports of COVID-19 in droplets and aerosols was the best way infections came from China, sometime to travel between individuals? How did in late 2019.1 Did the virus appear the virus know, you may ask?

14 — Rediscovering School Science | Oct 2020 Neither did the virus know, nor was influenza outbreak, and Ebola. All these What was causing the disease? How did it ‘designed’ for humans. All that diseases were initially zoonoses. This people acquire it? happened was that the virus combined means that they were, at one time, In the initial years after the outbreak, the features it already possessed as exclusively diseases of wild or domestic studies by various groups of scientists on an infectious agent in another animal animals that, at some point, started the area and the people infected with with an opportunity to infect a human infecting human beings instead (see Fig. the disease revealed two interesting being. This happens all the time. We 1). The rest is history. For example, the patterns linking them.5 One, people share homes and environments with plague, an old disease as far as zoonoses with these symptoms had all spent a go, has killed millions of people in the many domestic and wild animals. These day in the forest, shortly before they past 2000 years.3 But the frequency of animals often harbour viruses and fell sick. Since their symptoms were new zoonoses has skyrocketed since the bacteria that may or may not cause similar to that of Yellow Fever (a 20th century in comparison to any other diseases in them. We may not have disease in Africa and South America point in history. To understand some encountered many of these microbes that is transmitted from animals to reasons behind this, let us examine the earlier, but sheer physical proximity humans by day-biting mosquitoes in case of a zoonosis closer home — the increases opportunities for accidental tree canopies), scientists searched tree Kyasanur Forest Disease in the Western contact with them. It is also very canopies for day-biting mosquitoes.6 Ghats, India. likely that a large number of microbes Not finding any, they had to eliminate routinely come in contact with us, but the possibility of mosquitoes acting as not all of them are able to make the When does a virus transmission agents, or vectors, of this human body a home and cause disease. jump species? new disease. Two, often, people who Ever since the discovery, in 1907, that A mysterious new illness was first were infected had been in the presence the tuberculosis bacterium could be reported, in 1957, from the remote of dead monkeys in the days prior to passed from cows to humans through village of Kyasanur from the Shimoga developing symptoms. Residents of the raw milk, we have known that animals district in Karnataka.4 Around 500 village reported seeing hundreds of dead can pass on pathogens to us.3 Since people fell ill that year with very high monkeys in the neighbouring forests. then, many other discoveries have fever, splitting headaches, drowsiness, On investigation, scientists identified indicated the animal origins of some and delirium. Since this was nothing like ticks on the dead monkeys as potential of the deadliest diseases ever known the diseases known at the time, malaria vectors and, soon after, discovered a new to us, including plague, AIDS, the 1918 and typhoid were quickly ruled out. species of virus in the ticks as the cause of the mysterious illness (see Fig. 2). The disease came to be known as the Kyasanur Forest Disease (KFD) after the village where it was first discovered. The science of putting together pieces of puzzles related to disease outbreaks and spread is called epidemiology. Often, some pieces of a jigsaw may be hard to find, but testing hypotheses through careful observation and reasoning can help epidemiologists take steps that lead to the missing pieces. For example, establishing the link between ticks and the dead monkeys helped explain why there were no reports of transmission of

Fig. 1. Human history offers many examples of zoonoses. Credits: U.S. GAO report GAO-12-55, U.S. Government Accountability Office from Washington, DC, United States, Wikimedia Commons. URL: https://commons.wikimedia.org/ wiki/File:Figure_3-_Examples_of_Zoonotic_ Diseases_and_Their_Affected_Populations_ (6323431516).jpg. License: CC-BY.

— Rediscovering School Science | Oct 2020 15 When does a zoonosis become a pandemic? Since there is no evidence that humans had been exposed to the KFD virus before 1957, it seems likely that this disease was caused when people encountered it for the first time. This is similar to what happened with SARS- CoV-2 last year. The KFD virus couldn’t be transmitted from one human to another without a tick. By the time a tick that had taken a full blood meal from one human was ready to feed on another host, its chances of encountering another human, in a forest adjoining a remote village, were slim. In contrast, SARS-CoV-2 does not need a vector to move between humans. As we now know, it spreads through droplets and aerosols. This makes it much easier for the virus to be transmitted between people, and enables its rapid travel across the world through interconnected air routes between distant countries. Fig. 2. Like mosquitoes, ticks of domestic and wild animals can act as vectors or transmission agents of human pathogens. Thus, the pandemic. Credits: Fairfax County, Flickr. URL: https://www.flickr.com/photos/fairfaxcounty/7209178448. License: CC-BY-SA. Parting thoughts Zoonoses can be triggered by opportunities that bring humans, KFD between humans. In most cases, a an animal of one species to another. domestic animals, and wild animals tick bites a person once, lingers on long If the other species happens to be a closer to each other. Over the years, we enough to get a full blood meal, then monkey or human, the virus causes have seen that the symptoms of KFD in drops off without looking for another serious illness, even death. These linked humans are very similar to those caused host (or person) to bite. Since the tick patterns of movement of the virus are by zoonotic viruses found in Russia and bite transmits the virus to the person it called transmission cycles (see Fig. 3). Saudi Arabia.4 Similarly, SARS-CoV-2 has feeds on, this person develops symptoms The transmission cycle of any zoonosis many close relatives in various animal of the disease. The only way in which involves a primary host, a transmission hosts, including bats and pangolins. the virus would be able to move out of agent or vector, and a secondary host. While we are yet to piece together the the infected person’s body is through For a virus, the primary host is usually origins of this virus, the close proximity their blood. Interestingly, mosquitoes of these animals to humans is the only a wild or domestic animal or bird. The can potentially transmit this virus plausible reason for SARS-CoV-2 to have vector may be an insect, as in the KFD quite effectively (since they bite many ‘jumped’ hosts. people), but seem not to do so. or Yellow Fever; or even just saliva droplets in the air, as in the case of The suspected source of the pandemic So how does the virus reach humans Swine Flu or Bird Flu. Human beings are — a crowded market in China that in the first place? Many years of usually secondary hosts. Understanding sold wild animals, including bats investigation by epidemiologists and pangolins — would provide the the transmission cycle of a zoonosis and virologists has revealed that the virus with plenty of opportunities to can be quite challenging. For example, KFD virus can live, without causing make the jump to humans. Similar symptoms of infection, in many wild discovering it for the KFD virus took opportunities arise due to large-scale mammals like Sambar and Bison, and many years of investigation in remote farming of pigs and chickens, the domestic animals like goats and cattle.5 and difficult terrain, limited equipment suspected sources of swine flu and bird It jumps species only when a tick that and intermittent funding, multiple flu respectively. Crowded conditions has had an incomplete meal jumps from twists, and wrong turns.5 allow a virus to multiply and evolve,

16 — Rediscovering School Science | Oct 2020 Fig. 3. The transmission cycle of the KFD virus. Credits: Centers for Disease Control and Prevention, National Center for Emerging and Zoonotic Infectious Diseases (NCEZID), Division of High-Consequence Pathogens and Pathology (DHCPP), Viral Special Pathogens Branch (VSPB). URL: https://www.cdc.gov/vhf/kyasanur/images/kyasanur-virus-ecology.jpg. License: CC-BY-3.0. while also increasing opportunities known to humans today, like HIV and indicate that increasing pressures of for it to move between species. Ebola, are zoonoses from wild animals. food production and land are likely Moving deeper into forests, clearing In one wide-ranging study, hundreds of to result in larger animal farms and them for agriculture, and settling in new species of viruses were discovered further forest destruction. If the stories the neighbourhood of these forests across multiple species of animals of zoonoses emerging in humans in increases our chances of contact with in different parts of the world.7 At the last century are anything to go by, reservoirs of viruses found in wild present, we do not know if these have this can only increase the potential for animals. KFD as well as some of the the potential to jump hosts and cause future pandemics like COVID-19. most infamous and deadly diseases pandemics. However, the numbers

— Rediscovering School Science | Oct 2020 17 Key takeaways

• The many zoonoses that have shaped human history were caused by microbes that were once exclusively found in wild or domestic animals. • Sheer physical contact with wild or domestic animals increases the chances of the microbes they harbour jumping species to infect us. • The capture and sale of wild animals, large-scale farming of livestock, and clearing of forests for human habitation can all increase our chances of contact with new microbes. • Not all of the many microbes that we routinely come in contact with are able to make the human body a home and cause disease. • Depending on its mode of transmission, a zoonosis can remain endemic to an area or become a pandemic by spreading simultaneously worldwide. • Piecing together the transmission cycle (the primary host, vector, and secondary host) of a zoonosis can be quite challenging and time-intensive. • Due to increasing pressures of food production and land, the frequency of new zoonoses has skyrocketed since the 20th century.

Note: Source of the image used in the background of the article title: https://www.flickr.com/photos/vijo/515712475. Credits: Vivek Joshi, Flickr. License: CC-BY.

References: 1. Archived: WHO Timeline - COVID-19. World Health Organisation. URL: https://www.who.int/news-room/detail/27-04-2020-who-timeline---covid-19. 2. Clinical Questions about COVID-19: Questions and Answers. Centre for Disease Control & Prevention. URL: https://www.cdc.gov/coronavirus/2019-ncov/hcp/ faq.html#Transmission 3. Control of zoonoses in Britain: past, present, and future. British Medical Journal. URL: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1549006/pdf/ bmjcred00568-0027.pdf. 4. Kyasanur Forest Disease (KFD). Centre for Disease Control & Prevention. URL: https://www.cdc.gov/vhf/kyasanur/index.html. 5. The Seven-Decade Transnational Hunt for the Origins of the Kyasanur Forest Disease. The Wire Science. URL: https://science.thewire.in/health/kyasanur-kfd- rajagopalan-boshell/. 6. Transmission of Yellow Fever Virus. Centre for Disease Control & Prevention. URL: https://www.cdc.gov/yellowfever/transmission/index.html. 7. Global trends in emerging infectious diseases. Nature. URL: https://www.nature.com/articles/nature06536.

Thejaswi Shivanand is part of Centre for Learning, Bangalore. He teaches Biology, Statistics, and Geography in the senior school. He is also closely involved with the school library and nature education at CFL. He can be contacted at [email protected].

18 — Rediscovering School Science | Oct 2020

CATS, DOGS, HOUSEFLIES SNIPPETS & SARS-CoV-2

Can SARS-CoV-2 be transmitted to us virus to uncovered food. Or a fly carrying the virus could through cat or dog bites? transmit it to a person, when it sits on their skin. SARS-CoV-2 most likely jumped from wild bats or However, no cases of transmission via the fecal- pangolins to humans. However, currently there is no oral route have been reported for SARS-CoV-2 as of evidence to suggest that domesticated animals can now. Therefore, infection via this route is unlikely in transmit this virus to humans. quarantine facilities, hospitals, or while an infected person is under self-isolation. Even if a fly carrying the A recent study showed that SARS-CoV-2 can successfully SARS-CoV-2 virus sat on our skin, it cannot infect us infect cats and ferrets, and both species produce an through clear, unbroken skin. immune response against the virus. However, the virus is not able to successfully multiply in dogs. SARS-CoV-2 is also unable to infect pigs, chickens, and ducks. Further experiments are necessary to know whether pets can transmit SARS-CoV-2 to humans, and vice versa. As a precaution, if you have COVID-19 symptoms, avoid close contact with animals, including pets. Wash your hands after handling any animals, their food, waste, or supplies. Practice good pet hygiene, and clean up after your pets properly.

Do houseflies spread SARS-CoV-2 infection? A Bollywood actor claimed that the SARS-CoV-2 virus is found in the stools of some COVID-19 patients, even a few days after they have recovered. If this were true, a fly Credits: Simon Berry. URL: https://www.flickr.com/photos/ that has sat on the stool of an infected person (in cases colalife/8549300746. License: CC-BY-SA. of open defecation) could transport the SARS-CoV-2

Notes: 1. These responses were first published on the Indian Scientists’ Response to CoViD-19 (ISRC) website. 2. Source of the image used in the background of the article title: https://www.needpix.com/photo/1911735/dog-cat-cats-animals-cute-feline.

— Rediscovering School Science | Oct 2020 19 THE INFECTION WHAT DO WE KNOW ABOUT SARS- CoV-2?

SHAHID JAMEEL

How do we know that or some time now, scientists have Coronaviruses cause acute and persistent SARS-CoV-2 is a 'novel' predicted the emergence of “Disease infections in humans, other mammals, coronavirus? How was FX”, a hypothetical unknown disease and birds. Members of this family were agent that would be capable of causing isolated from animals as early as in the this virus discovered? a future epidemic. In December 2019, 1930s. But it was only in the 1960s that What do we know the world woke up to the news of a new some viruses causing respiratory disease about its structure? virus. Initially referred to as the 2019 in humans were discovered to be part of How long can it remain novel coronavirus, it was later renamed as infectious outside a SARS-CoV-2. host cell? Is there any evidence to suggest that A novel coronavirus SARS-CoV-2 may have The ‘SARS’ in its name reflects the originated in a lab? symptoms this virus produces in some infected people — Severe Acute Respiratory Syndrome, and ‘CoV-2’ refers to the fact that it is the second coronavirus found to produce these symptoms (the first one emerged in 2002-03 and was called SARS-CoV). Coronaviruses are a group of viruses with surface spikes, visible under a very Fig. 1. Electron micrograph of SARS-CoV-2 high-powered electron microscope, that particles with visible coronae. Virus particles give them a solar corona or crown-like are shown emerging from the surface of cells cultured in the lab. (hence the name) appearance (see Fig. 1). The disease this virus causes is called Credits: NIAID Rocky Mountain Laboratories (RML), U.S. NIH. URL: https://www.flickr.com/photos/ Coronavirus Infectious Disease 2019, niaid/49534865371/in/album-72157712914621487/. abbreviated as COVID-19. License: CC-BY.

20 — Rediscovering School Science | Oct 2020 this family. Four human coronaviruses embedded in its lipid (fat) envelope. modifying cellular processes in the host were identified as being endemic in the It is the S proteins that give the virus to better replicate the virus. human population. These cause about its corona-like appearance. Within While a genome of 30,000 bases in 20% of common colds annually. the envelope, a single strand of RNA coronaviruses is unusually large for of about 30,000 bases or nucleotides Novel viruses are emerging all the an RNA virus (most are about a third is tightly wrapped around multiple time, but come into prominence only of this), its size is not important for when they cause disease in humans or copies of the Nucleocapsid (N) protein (see Fig. 3). During infection, the virus transmission or severity of disease. Large other animal species. In the past two population sizes and a high frequency decades, three new human coronaviruses RNA enters a host cell, replicates, and of errors introduced during genome have emerged, all from bats, to cause directs the synthesis of about 24- replication mean that viruses tend to outbreaks in different parts of the world. 27 proteins that allow the virus to show high mutation rates. In general, These include the SARS-CoV in 2002-03 multiply. Some of these proteins, like RNA viruses mutate even faster than in China, the Middle East Respiratory the viral replicase enzyme and the S, E, Syndrome Coronavirus (MERS-CoV) M and N proteins, help in direct ways. DNA viruses because their replicases in Saudi Arabia in 2012, and the most Several nonstructural proteins, such as (enzymes which catalyze the synthesis recent SARS-CoV-2 in China in 2019. the Orf3a protein, help indirectly by of a complementary RNA molecule All these viruses have similar physical attributes and genome organization, but differ in their genetic sequences. For example, SARS-CoV-2 has ~80% sequence identity with SARS-CoV, but only ~55% to MERS-CoV, and ~50% to the common cold coronaviruses.

What do we know about SARS-CoV-2? In late 2019, doctors in China’s Hubei Province, and its main city Wuhan, started seeing a cluster of patients with pneumonia. This is an infection of the lung in which the air sacs are inflamed and may fill with fluid or pus, causing cough, fever, chills, and breathing difficulties (seeFig. 2). While pneumonia is seen in infections by many microorganisms (bacteria, viruses, and fungi), genetic sequencing of fluid from the lungs of patients from Wuhan always showed the presence of virus sequences similar, but not identical, to SARS-CoV. The virus was isolated from cell cultures infected with fluids from the lungs, throat, and nasal cavity of patients. Thus, powerful detection tools, cell culture, and genetic sequencing technologies ensured that the virus was identified within just a few weeks. Like other coronaviruses, SARS-CoV-2 is a particle of about 100 nanometers –9 Fig. 2. The discovery of COVID-19 was sparked by a cluster of patients with pneumonia in (1 nanometer = 10 meter) in size. This Wuhan, China. Lung infection can lead to fluid accumulation in air sacs that results in enveloped virus has three different breathing difficulties. proteins — the Spike (S), Envelope Credits: National Institutes of Health, United States Department of Health and Human Services, Wikimedia (E), and Membrane (M) proteins — Commons. URL: https://commons.wikimedia.org/wiki/File:New_Pneumonia_cartoon.jpg. License: CC-BY.

— Rediscovering School Science | Oct 2020 21 Origin of SARS-CoV-2 Where did SARS-CoV-2 come from? Evidence indicates that it jumped into humans from bats, either directly or via another animal species (in this case, the pangolin — a scaly mammal whose flesh is eaten in China, and scales are used in Chinese traditional medicine). What is the evidence? The SARS-CoV-2 genome has 96% sequence identity to coronaviruses isolated from bats in eastern China in 2018, and 91% identity to coronaviruses isolated from pangolins. This is much higher than its Fig. 3. Artist’s model of a SARS-CoV-2 particle. An estimated 100 trimers (or 300 monomers) of S, about 2000 copies of M, and about 20 copies of E are deeply embedded in the lipid genetic identity to SARS-CoV (~80%), envelope of each virus particle. Within the envelope, an RNA strand of 30,000 bases is tightly MERS-CoV (~55%) and other human wrapped around multiple copies of the Nucleocapsid (N) protein. coronaviruses (~50%), suggesting that Credits: Created by Maya Peters Kostman for the Innovative Genomics Institute. URL: https:// SARS-CoV-2 is not derived from the innovativegenomics.org/wp-content/uploads/2020/04/Single-virion-with-all-parts-labeled.png. License: earlier human viruses. Two key features CC-BY-NC-SA. in the Spike proteins of SARS-CoV-2 allow it to bind human cells and using an RNA template) lack an error- 24 hours on cardboard, and 72 hours on transmit efficiently. One of these is correction function. Higher mutation plastic and stainless steel. In laboratory found in Pangolin-CoV, but both are rates lead to more diverse virus tests, SARS-CoV-2 can be inactivated missing from Bat-CoV. The most likely populations, some of which randomly within seconds at temperatures of 90oC scenario is that a progenitor of SARS- acquire the ability to survive or transmit or above. It is highly stable at 4oC, and CoV-2 jumped to humans from bats, better. However, due to an enzyme that stays infectious at 22oC for 7 days, 37oC possibly through pangolins. The virus repairs replication errors, coronaviruses for 1 day, 56oC for 10 min, and 70oC for then mutated and evolved in humans, tend to have lower mutation rates that 1 min. A 1:100 dilution of household till such time that it became capable of efficient transmission, and started are, for example, about 1000 times bleach (4% sodium hypochlorite) is causing widespread respiratory disease. lower than that for influenza viruses helpful in disinfecting surfaces, but (also RNA viruses). should not be used on human skin as it Was SARS-CoV-2 developed in a lab? If As of now, only one strain of SARS- can cause irritation, especially in the eyes. one tried to develop a highly pathogenic CoV-2 is circulating globally. But this strain has multiple groups (or clades) of isolates, which often show variations Box 1. Protection from SARS-CoV-2 infection: in geographic distribution. Since its There are three important guidelines to protect from infection. emergence, one mutant of the virus, 1. Masks: Though viruses are extremely small (nanometers) and are able to pass with an aspartic acid to glycine change through very fine filters, SARS-CoV-2 and other respiratory viruses are released at amino acid 614 in a Spike protein, in large and small droplets while coughing, sneezing, speaking, or even breathing. has spread faster than others. Scientists Inhaling these droplets can infect a susceptible person. Wearing a mask, even a believe that this mutation (called home-made cloth one, allows an infected person to contain the release of these D614G) has increased both the stability droplets, and a susceptible person to prevent exposure. If both wear masks, the of the Spike protein trimers and their chances of transmission are negligible. ability to bind cell surface receptors for 2. Physical distancing: Maintaining a distance of at least 2 m (or 6 feet) limits productive infection. exposure to large droplets, loaded with the virus, from an infected person. 3. Hand hygiene: Virus-carrying droplets can contaminate surfaces such as door Since a virus is “living” only when inside knobs, tabletops, etc. When a susceptible person touches these surfaces, the virus a host cell, we call it either infectious is transferred to their hands and, eventually, finds its way to their mouth or nose. or noninfectious when outside (see Since SARS-CoV-2 has a lipid (fat) membrane, washing hands with soap and water Box 1). SARS-CoV-2 can stay infectious destroys it just like soap cuts through grease. Hand sanitizers with about 70% on surfaces for variable times at room alcohol are also helpful. temperature — up to 4 hours on copper,

22 — Rediscovering School Science | Oct 2020 coronavirus, the logical starting point India also pointed this out erroneously recognize potential jumps well in would be another human coronavirus, and retracted their results. There is no advance. For example, India has 117 not an obscure bat or pangolin virus credible evidence that SARS-CoV-2 was indigenous species of bats, but we that has never been found to cause developed in a lab. All available evidence know very little about the viruses they disease in humans. The Nobel laureate seems to point to this virus being a harbour. Killing bats or other animals Prof. Luc Montagnier has referred to the product of natural evolution. is not the solution; they have valuable presence of elements of both the HIV-1 roles in our ecosystem. Surveillance and retrovirus and the malarial parasite Parting thoughts ensuring that their habitats (i.e., forests) Plasmodium falciparum in the SARS- Can a bat virus jump into humans are not destroyed will reduce animal- CoV-2 genome. These short sequences, again? Absolutely. So can viruses from human contact, and reduce the risk as discovered by scientists in 2005, rodents, monkeys, and other mammals. of animal viruses getting into human are required for genome replication We must, therefore, carry out routine populations. This is the only way to by many coronaviruses. Researchers in surveillance of our ecosystems to avoid future disease outbreaks.

Key takeaways

• SARS-CoV-2 gets its name from the fact that it is the second coronavirus known to cause Severe Acute Respiratory Syndrome in humans. Like other coronaviruses, SARS-CoV-2 is an RNA virus with a crown-like appearance when viewed under an electron microscope. • While SARS-CoV-2 has an unusually large genome, its mutation rate is on average lower than other RNA viruses. As of now, only one strain of SARS-CoV-2 is circulating globally, and one mutation (called D614G) has spread faster than others. • SARS-CoV-2 can stay infectious on a variety of surfaces for variable durations, but can be easily killed with soaps or disinfectants. • There is no credible evidence that SARS-CoV-2 was created in a lab. All available evidence points to it being a product of natural evolution that originated in bats, and jumped to humans directly, or via pangolins. • Future outbreaks of zoonoses from wild animals can be avoided by routine surveillance of ecosystems and ensuring that their (forest) habitats are not destroyed.

Note: Source of the image used in the background of the article title: https://phil.cdc.gov/Details.aspx?pid=23312. Credits: Alissa Eckert, MSMI & Dan Higgins, MAMS, created at the Centers for Disease Control and Prevention (CDC). License: Public Domain.

Shahid Jameel is a former Group Leader of Virology at The International Centre for Genetic Engineering and Biotechnology (ICGEB), New Delhi. He is now the CEO of the DBT/Wellcome Trust India Alliance.

— Rediscovering School Science | Oct 2020 23 SNIPPETS

WILL STEAM INHALATION OR NASAL RINSES CURE A SARS-CoV-2 INFECTION?

There is no evidence to suggest that steam inhalation and One needs to be careful when using either of these nasal rinses kill viruses in the respiratory tract. In fact, methods. Hot water or steam can cause severe burns or one controlled study found that steam inhalation did not scalds if handled without care. Similarly, if the water used reduce viral load in the nasal passage. for nasal irrigation is hot (instead of warm), or has a high Steam inhalation is often used to provide relief from salt concentration, it can cause irritation or discomfort common symptoms of respiratory illnesses, such as nasal in the nose. If the water or irrigation device in unclean, congestion, a runny nose, or cough. Some studies found there is an additional risk of catching infection. Note that this method does help in reducing symptoms, while that these treatments are not listed on the World Health others found that these symptoms persist even after a Organisation (WHO) or Centers for Disease Control and steam inhalation. However, symptoms did not worsen in Prevention (CDC) websites for treatment or prevention any of these studies. Since nasal rinses or irrigation can of COVID-19. This means that even if you are using give symptomatic relief in case of upper respiratory tract these methods, it is critical to follow physical distancing, infections such as sinusitis and allergic rhinitis, they are handwashing, and other precautions recommended for recommended for patients suffering from these symptoms. protection from COVID-19.

Notes: 1. This response was first published on the Indian Scientists’ Response to CoViD-19 (ISRC) website. 2. Source of the image used in the background of the article title: https://www.pickpik.com/gray-pressure-cooker-kitchen-cook-pots-cooking-pot-60103.

24 — Rediscovering School Science | Oct 2020 THE INFECTION

WHAT DO WE KNOW ABOUT

COVID-19? SATYAJIT RATH

How does SARS-CoV-2 ARS-CoV-2 is a virus. Viruses are Establishing infection very, very small particles that can infect the human body? SARS-CoV-2 particles enter the body, by stick to the surfaces of certain What factors help or S and large, through the nose and mouth cells (called host cells) in our body. This hamper infection? into the airways. So the first cells they sticking can only happen if the shape of meet and infect are the cells lining these Why do we see such a part of the virus surface matches the airways. The immune response of the body wide variation in the shape of a part of the cell surface. Only limits and contains these spots of infection. symptoms and signs when this sticking happens efficiently Large numbers of these infection spots can of the disease? Does can the virus particle get into the cell. cause problems for the functioning of the Once inside, the genetic information in SARS-CoV-2 affect airways. The virus particles can also spill the virus particle (like the RNA in SARS- children? And how over from these spots into the rest of the CoV-2) is brought into operation by the deadly is COVID-19? body, infecting cells in other parts, and biochemical processes of the cell. This increasing the problem. results in redirection of these processes towards making and assembling many Two factors help the virus infect us. copies of the virus particle. These copies The virus particle’s ability to stick can then emerge from the infected cell very efficiently to target cells, and (which often dies) and drift around. They the usability of the virus RNA by the can stick to many more new cells, not biochemical processes of many different only starting the cycle all over again, but cell types. The latter helps ensure that enlarging it. new virus particles will get made from

— Rediscovering School Science | Oct 2020 25 any cell type infected. Both are true of So far, there is no evidence that children and young adults less severely SARS-CoV-2 — it sticks very efficiently, different genetic strains of the SARS- than it affects the elderly, although and it can grow in most cell types. CoV-2 virus tend to cause more or less the symptoms seem to be similar in all Two factors can hamper infection. The severe illness. Currently, most of the groups. (There are rare instances of a most obvious one is to prevent the variation in illness seems to be due to quite distinct illness pattern in children, virus from getting into the body. This is differences between people rather than which is not yet well understood.) why measures like physical distancing, the virus. Two categories of people are However, this is not the same as masks, and frequent hand-washing are at higher risk of severe illness. One of ‘children being at low risk’. They will recommended. Secondly, pre-existing these appears mostly to be associated and do get infected. Also, while their immunity in the body, specifically with the existence of pre-existing own illness may be mild, children can against SARS-CoV-2, can prevent it, changes in the body’s inflammatory certainly spread the infection to other for example, from sticking efficiently responses. These are of the kind seen people, such as their grandparents, who to cells and entering them. This is what in obesity, type 2 diabetes, heart are at higher risk. It is useful to keep in will happen, hopefully, with effective disease, hypertension, chronic kidney mind that a large proportion of SARS- vaccination. or liver diseases, in the elderly, and CoV-2 infections are ‘asymptomatic’, (in a double whammy) in people with meaning without any symptoms at Infection symptoms pre-existing chronic airway-related all. Among the infected people who illnesses. As of now, there is little and signs do develop symptoms, cough is the evidence that asthma in particular commonest; only about a fifth of such Interestingly, most symptoms and signs predisposes to severe COVID-19 people show no cough at all. The next of infection are, in fact, symptoms and illness, although clinical researchers commonest is fever, although about a signs of the body’s response to the are looking for such associations. A third of infected people with symptoms infection! Since SARS-CoV-2 enters second category is of people with poor show little or no fever. Breathlessness is through the airways, most (though immune responses, such as cancer the commonest symptom in the severe not all) of the earliest symptoms will patients under chemotherapy. form of COVID-19. Screening for fever relate to the airways. Infection of cells The general indication from evidence at travel checkpoints is useful, but it of the airway lining causes irritation seems to be that COVID-19 affects is likely that the spread of the virus and cough. Depending on whether the upper airway remains extensively infected or not, there may or may not be a ‘cold’ (which simply means such a lot of fluid comes out from the airways that it drips out from the nose and throat!). One of the many ways the body responds to the virus is by resetting its temperature control system, meaning fever. Since this resetting is quite variable, there may be differences in this symptom, ranging from mild to severe fever. Widespread growth of the virus in the airways and lungs as well as the body’s response to it affect the normal functioning of the airways and cause breathlessness. When both spill over, beyond the airways and lungs, other symptoms appear (see Fig. 1). These symptoms will vary depending on where in the body the virus happens to establish a foothold, and how widespread the body’s response is. In other words, Fig. 1. The symptoms and signs of COVID-19 infection will vary depending on where in the the symptoms and signs of infection body the virus happens to establish a foothold, and how widespread the body’s response is. will then depend on which organs are Credits: Adapted from an image by Mikael Häggström, Wikimedia Commons. URL: https://commons. most affected. wikimedia.org/wiki/File:Symptoms_of_coronavirus_disease_2019.svg. License: CC-0.

26 — Rediscovering School Science | Oct 2020 Box 1. How is COVID-19 different from other viral infections? COVID-19 is likely more ‘dangerous’ than seasonal flu or If enough people get infected at the same time, then even influenza, in the sense that its ‘infection fatality rate’ is the small proportion of severely ill people will be in large likely to turn out to be higher. While the viruses causing numbers and overwhelm hospitals. these infections are likely to be equally contagious, how Measles, chickenpox and mumps all enter the body through ‘contagious’ a virus actually is will also depend on how the nose and mouth, but they spread outside these areas susceptible the population is. Many of us are at least a of the body quite often. These viruses are all MUCH more little bit resistant to seasonal flu because of prior exposure contagious than either flu or COVID-19. Because they to similar viruses, but that does not seem to be the case are so common, many adults tend to have met them and with COVID-19. This is likely to increase the actual rate of developed resistance. Therefore, most actual cases are in spread of SARS-CoV-2. Once again, this is why, even though children. Measles can cause death about as frequently as COVID-19 infection does not put every individual who is seasonal flu does, while chickenpox and mumps are much infected at major risk of severe illness, it is a societal problem. less lethal than that.

from an infected individual starts a few CoV-2 put the number at much below words, every individual who is infected days before that individual develops 1%. Even among the categories of is not at major risk of severe illness, let symptoms. people at extremely high risk of severe alone of death. The spread of infection COVID-19 illness, the eventual infection is a problem because if enough people Fatality rates fatality rate is unlikely to exceed 5%. get infected at the same time, then even the small proportion of severely Knowing exact numbers for However, nobody can predict, with ill people will be in large numbers measurements such as death rates for absolute accuracy, what the course and hospitals will be overwhelmed. a pandemic is only possible when we of illness will be in an individual. All This spread can be reduced by look back at it. The so-called ‘infection our information is statistical and quickly identifying individual cases in fatality rate’ is the proportion of death based on likelihoods, not guarantees. communities, careful and rapid tracing amongst all infected people. Since Good medical facilities will make the of their contacts, providing every so many SARS-CoV-2 infections are difference between life and death in kind of support to infected/exposed asymptomatic, this number is impossible people with severe illness. Severe illness individuals during their isolation, to determine accurately at the moment. is characterised by extensive lung and increasing our public hospital We need much more evidence of involvement, with severe breathlessness ‘exposure’ from surveys that will take a capacity. Isolation needs to be seen and/or symptoms of other organs being long time to collect. The so-called ‘case as an action that infected or exposed affected. At such stages, if comparable fatality rate’, which is widely discussed individuals undertake for the good of medical-health facilities are available, as being between 2-8%, is also quite the community, and not for their own the outcomes for severely ill COVID-19 inaccurate. This rate is the proportion sakes. This needs to be coupled with a patients are likely to be the same of death amongst all infected and cultural acceptance by society at large everywhere in the world. However, symptomatic ‘cases’, but what degree of a new norm of physical (NOT ‘social’!) medical facilities are not comparable of severity is to be called a ‘case’ varies distancing along with the use of across the world and are, in fact, even a lot from place to place and from time face-and-nose-coverings and frequent less comparable between the well-off to time. Nonetheless, what we do know hand cleaning. Clearly, we — both the and the poor in the same place. is that SARS-CoV-2 infection is not as government and society — are failing dangerous as other coronaviruses we miserably on most (if not all) of these have met earlier, such as SARS-CoV or Parting thoughts fronts, and have simply been using MERS-CoV (see Box 1). In fact, all the In this context, it is important to keep versions of the so-called ‘lockdown’, very approximate estimates and guesses in mind that SARS-CoV-2 infection is including but not limited to keeping of the infection fatality rate of SARS- not a major individual risk. In other schools closed, as a (bad) substitute.

— Rediscovering School Science | Oct 2020 27 Key takeaways

• That SARS-CoV-2 sticks efficiently to target cells and grows in most cell types in the human body aids its ability to infect us. • Preventing entry to the virus (through physical distancing, use of face masks, and hand hygiene), and developing immunity through effective vaccination can hamper SARS-CoV-2 infection. • The symptoms and signs of COVID-19 infection vary depending on where in the body the virus happens to establish a foothold, and how widespread the body’s response is. • Most variations in illness seem to be due to differences between people rather than the virus. People with pre-existing changes in the body’s inflammatory responses and poor immune responses are more susceptible to severe illness. • Evidence suggests that COVID-19 affects children and young adults less severely than it affects the elderly. Children can spread the infection to people at risk, including their grandparents. • It is difficult to know exact numbers for measurements such as death rates at this stage of the pandemic. But eventual infection fatality rates are unlikely to exceed 5% even among people at extremely high risk of severe COVID-19 illness.

Note: Source of the image used in the background of the article title: https://pixabay.com/illustrations/coronavirus-sars-cov-2-lung-4924022/. Credits: Geralt, Pixabay. License: CC-0.

Satyajit Rath is currently a Visiting Professor at the Indian Institute of Science Education and Research (IISER), Pune. He was formerly a scientist at the National Institute of Immunology (NII), New Delhi.

28 — Rediscovering School Science | Oct 2020 SNIPPETS

ARE PEOPLE FROM NORTHEAST INDIA SPREADING THE SARS-CoV-2 INFECTION?

COVID-19 is a zoonotic disease caused by the SARS-CoV-2 and insecurities pertaining to Jewish communities during virus. This means that the virus has jumped to humans the plague pandemic (Black Death) in Europe, to Africans from animals. Studies indicate that this spill-over to during the Ebola pandemic, and to Chinese in Hong Kong humans happened outside the country, and has nothing to during the SARS-CoV pandemic. In each of these cases, do with any particular community or ethnic group in India. certain people were discriminated and stigmatized due to Therefore, there is no evidence to suggest that people from fears of their association with the spread of the disease. a specific region or of a certain ethnicity are more likely to These reactions are harmful and unfair to those being spread this virus than others. persecuted. Such rumours can create social unrest, and divide us along ethnic, regional, and national lines. Such unfounded and unsubstantiated rumours are not unique to this pandemic. Historians have reported phobias ANY person, irrespective of their ethnic origin, caste, religion, or nationality, who has been in contact with a person with a SARS-CoV-2 infection can get infected. ANY infected person can spread the infection to others if they do not use a mask, or follow quarantine procedures and other precautionary measures. In this regard, we quote the Ministry of Health and Family Welfare, Government of India: “Public health emergencies during an outbreak of communicable diseases may cause fear and anxiety, leading to prejudices against people and communities, social isolation, and stigma. Such behaviour may culminate in increased hostility, chaos, and unnecessary social disruptions. There is an urgent need to counter such prejudices, and to rise as a community that is empowered with health literacy, and responds Credits: Chaipau, Wikimedia Commons. URL: https://commons.wikimedia. appropriately in the face of this adversity.” Humanity org/wiki/File:India-locator-map-NE.svg. License: CC-BY-SA. survives when together, and falls when divided!

Notes: 1. This response was first published on the Indian Scientists’ Response to CoViD-19 (ISRC) website. 2. Source of the image used in the background of the article title: https://pixabay.com/photos/coronavirus-corona-virus-covid-19-4958989/. Credits: thiagolazarino, Pixabay. License: CC-0.

— Rediscovering School Science | Oct 2020 29 SNIPPETS

ARE PEOPLE LIVING AT HIGH ALTITUDES & IN NORTHEAST INDIA PROTECTED FROM SARS-CoV-2 INFECTION DUE TO HIGHER UV EXPOSURE?

Electromagnetic radiation in the Ultraviolet (UV) wavelength SARS outbreak). Subsequent studies showed that SARS-CoV is generally harmful to living organisms. There are three can be completely inactivated in 15 minutes by increasing subtypes of UV light: the intensity of the UVC lamp to ~4 mW/cm2. However, the same study showed that there was no obvious virus z UVC (200-280 nm): UVC is absorbed by RNA and DNA bases, and can damage them photochemically. It is, inactivation using UVA. In the laboratory, far-UVC (222 nm) however, completely filtered out by the ozone layer. can kill influenza viruses without damaging mammalian cells. However, none of these experiments have been z UVB (280-320 nm): UVB can also cause damage to RNA performed in humans yet. Importantly, trying to disinfect and DNA bases, but it is 20-100 times less efficient than one’s skin with UVB/C light can cause skin irritation, UVC. Almost 90% of UVB is absorbed by the ozone layer. sunburn, vision impairment and, sometimes, skin cancer. z UVA (320-400 nm): UVA is the major UV component Finally, even though UV irradiance increases with altitude in sunlight (~95%) that reaches the Earth’s surface. (~10-12% per kilometre), the UV index (which measures Thus, by the time solar radiation reaches the Earth’s the strength of sunburn producing UV radiation) in many surface, its UV component is not sufficient to kill viruses. regions in the Indian Northeast are similar or lower For example, a study showed that a UVC light intensity compared to the rest of the country. This means that hilly of > 90 uW/cm2 for about 60 minutes is required to areas or the Northeast states are not necessarily protected inactivate the SARS-CoV virus (which caused the 2003 from COVID-19 infection due to UV radiation from the sun.

Notes: 1. This response was first published on the Indian Scientists’ Response to CoViD-19 (ISRC) website. 2. Source of the image used in the background of the article title: https://commons.wikimedia.org/wiki/File:Gurudongmar_Lake-North_Sikkim.jpg. Credits: Sandeep pai1986, Wikimedia Commons. License: CC-BY-SA.

30 — Rediscovering School Science | Oct 2020 THE INFECTION

COVID-19: SYMPTOMS & SPREAD N. D. HARI DASS, SHANTALA HARI DASS, KAMAL LODAYA & R. V. VANDANA

What symptoms does one OVID-19 is a pandemic caused by Symptoms the SARS-CoV-2 virus. Once the experience if they have The early infection stage lasts about a virus enters our body, it infects COVID-19? How long C week. People experiencing this stage of cells in the respiratory tract, replicates does it take to recover infection may experience mild symptoms within them, and releases new viral from infection? When of dry cough, fever, fatigue, and muscle particles that can, in turn, infect other pain. A small fraction might develop is hospitalization likely cells. This incubation period typically to be necessary? Can a short-lived bout of diarrhoea, sore extends between 1-5 days, but can in throat, or headache. Some people seem asymptomatic people some cases extend up to 14 days. Since to lose their sense of smell or taste. spread the infection? there are no signs of the host’s immune None of these symptoms are found in What precautions help system fighting the virus, tests for all patients (and different sources report minimize the risks antibodies in an infected person’s blood differing fractions). Since many diseases of transmitting the sample will appear negative. Screening have such symptoms, it may be hard to infection? for viral RNA in their swab/saliva sample figure out if the person showing them might also appear negative. However, has COVID-19 or not. Even a physician people in this stage of infection are may advise an observation period to see capable of shedding the virus (through if there are any changes in symptoms. their breath, sneeze, cough, saliva, and One in six patients, particularly those touch) and infecting other people. Once with pre-existing health problems, they appear, symptoms vary depending may transition into the progressive upon the stage of infection. stage of infection, and start showing

— Rediscovering School Science | Oct 2020 31 breathing difficulties on Days 5-6 (with (see Table I). The good news is that 82% or uncontrolled diabetes. The other Day 1 marking the start of symptoms). of symptomatic patients experience category includes caregivers, nurses, It is useful to measure the patient’s only mild or moderate symptoms doctors and other health workers with respiration rate (the normal rate is 12- that do not require hospitalization. prolonged exposure to infected people 16 breaths a minute at rest) while at rest After the first week of infection, their and higher viral “loads”. or sleeping. Change in respiration rate is symptoms reduce, and they begin to an indication that the person may have become better. Fully asymptomatic Spread COVID-19, and a doctor or a hospital patients recover without showing Anyone infected with the virus — should be contacted. If their breathing any symptoms at all. Taking a swab/ whether they are symptomatic, in difficulties become more severe, patients saliva sample from an infected person the incubation phase, or are fully may need to visit a hospital. Around typically gives a positive result a week asymptomatic — can shed and spread Day 8, roughly 5-15% of patients start after infection, and a negative result the virus for 21 days. Every time an experiencing build-up of fluid in their after 10 days. Much fewer people infected person sneezes or coughs, they lungs. This is pneumonia. Problems experience severe symptoms. These with blood clotting in blood vessels and become apparent during the progressive eject milli (100-1000 microns in size; capillaries may become predominant stage of infection (Day 7). This category 1000 microns make 1 millimetre) and in this stage. Some patients experience includes late symptomatic patients who micro (1-10 microns in size) droplets relief from breathing difficulties a week may show no symptoms at all in the from the nose or mouth. It is through into this stage. Recovering patients early infection stage; the first symptoms these droplets that the virus (each about may be discharged with the instruction they show are breathing difficulties in 0.1 micron in size) is expelled into the to remain in self-isolation for the next the progressive stage of the disease. surrounding air. Microdroplets can also 7-14 days. For the 4-5% of patients who Other late symptomatic patients may be ejected when infected people sing or progress into the advanced infection not show breathlessness, but the oxygen talk, or even when they breathe out. stage (marked with severe symptoms), levels in their blood reduce (this can A healthy individual can come into hospitalization can extend up to Day be immediately tested with a pulse contact with these expelled viruses in 42. If the patient’s symptoms continue oximeter) to a level that can be quite multiple ways (see Fig. 1). One route is deteriorating, they may be admitted serious. Symptoms associated with the through close contact with droplets from into the Intensive Care Unit (ICU) within advanced stage of infection are seen an infected person. Keeping a distance 2-3 days. Some patients may develop only in severe cases. Deaths start to of at least 2 m (or 6 feet) from other sepsis, a life-threatening condition that occur in this category of patients from people, referred to as physical distancing, can lead to multiple organ failure. Those the third day of the advanced infection can help minimize this risk. Another who show signs of Acute Respiratory stage. Late symptomatic patients may route is when our eyes, nose, or mouth Distress Syndrome (ARDS) might be put face the greatest danger. For those who comes into direct contact with micro- on a ventilator. Some patients may not do not survive the virus, the average droplets floating in the air (like aerosol become better. number of days from onset of symptoms sprays used for perfumes). These droplets until death is 18-19 days. It’s important to remember that not can remain suspended in the air for as every infected person experiences all Two categories of people seem more long as 10-15 minutes in a confined three stages. Also, the symptoms in prone to severe disease. One category space. Some researchers have referred each of these stages of infection can consists of infected people (young or to this route as airborne transmission show individual variations in severity old) with heart disease, lung disease, (a term that, until recently, was used to define the main route of transmission of highly contagious diseases like measles, Table I. Stages of infection in different categories of infected individuals. chicken pox, and tuberculosis). Wearing An infected individual may develop mild, moderate, or severe symptoms depending on the masks and avoiding crowded places stages of infection they experience. Some may develop symptoms very late (late symptomatic reduces the chances of being infected in cases), and some may not develop any symptoms at all (fully asymptomatic cases). this way. For “across-the-counter” shop, Mild or Fully Late bank and office transactions, masks and Stage of infection moderate asymptomatic Severe cases symptomatic physical distancing are crucial. A third cases cases cases route of transmission is through contact I. Incubation or with physical surfaces — like hard 1-5 days 14-21 days 1-5 days 6-13 days early infection plastic and steel — that milli-droplets II. Progressive 7 days – 7 days 0-7 days settle upon. The viral load on a physical surface degrades rapidly over time. But III. Advanced – – 7-28 days 7-28 days if we touch our face immediately after

32 — Rediscovering School Science | Oct 2020 touching these surfaces, the virus can be transferred from our hands to our eyes, nose, or mouth. This risk can be minimized if we avoid touching our face with unwashed hands, and frequently wash our hands with soap. How many viruses are sufficient to infect another person? Perhaps 1000 viruses are enough. But not everybody infects others in the same way. Although asymptomatic individuals may shed and spread the virus for 21 days after exposure to it, many do not spread the virus much. Some infected people, called super-spreaders, can release up to one lakh viruses every minute, but there is no known method Some of recognizing them. The spread of the Fig. 1. SARS-CoV-2 spreads through contact with droplets from an infected person. people catch the infection through close contact with these secretions or droplets. Others virus can also vary depending on the catch it by direct contact with micro-droplets that can remain airborne for as long as 10-15 nature and context of social interactions minutes in a confined space. Yet others can catch it indirectly. This happens when a person (see Table II). In general, outdoor touches their face with their hands immediately after touching a physical surface that interactions are better than those that milli-droplets have settled upon. happen indoors, large spaces are better Credits: Adapted from an image from Cirrincione, L.; Plescia, F.; Ledda, C.; Rapisarda, V.; Martorana, D.; than confined ones, low people density is Moldovan, R.E.; Theodoridou, K.; Cannizzaro, E. COVID-19 Pandemic: Prevention and Protection Measures to Be Adopted at the Workplace. Sustainability 2020, 12, 3603. License holder: MDPI, Basel, Switzerland. better than high, and short interactions URL: https://reflectionsipc.com/2020/03/12/considering-the-role-of-environmental-contamination-in- are better than longer ones. the-spread-of-covid-19/. License: CC-BY

Table II. The spread of COVID-19 can vary depending on the nature and context of social interaction.

Activity Viruses released/Exposure time/Risk Precautionary measures

Breathing ~ 20 viruses per minute Mask, distancing

Speaking ~ 200 viruses per minute Mask, distancing

Cough Lakhs of viruses per cough Distancing

Sneeze Lakhs of viruses per sneeze Distancing

Caregiver with carrier (of infection) Below 45 minutes Mask, distancing

Talking to carrier Below 5 minutes Mask

Passing by carrier Low risk Mask

Well-ventilated space Low risk Distancing

Narrow space High risk Mask

Shopping Medium risk Mask, entry in small batches

Public bath/toilet High surface-transmission risk Disinfect

Restaurants/temples High risk Outdoors, entry in small batches

Workplaces/schools High risk From home/online

Parties/weddings Very high risk —

Meetings/conferences Very high risk Online

Concerts/cinemas Very high risk —

— Rediscovering School Science | Oct 2020 33 Parting thoughts Unlike cholera, malaria or dengue, Since travel contributes to spread, the crowded areas, using a mask to cover COVID-19 spreads mainly through risks associated with it can be minimized the nose and mouth in public spaces, human contact. Unfortunately, a large by testing travelers in stations and physical distancing from other people, number of people are still complacent airports and encouraging them to and frequent washing of hands can all about the transmission of the disease. quarantine after their journeys. Avoiding help minimize the risk of infection.

Key takeaways

• Symptoms of COVID-19 vary during the incubation, early infection, progressive, and advanced stages of SARS-CoV-2 infection • Depending on the severity of symptoms, most of those infected with the virus recover after experiencing only mild symptoms, while some may show no symptoms at all (asymptomatic). • Those with severe symptoms, including those who are late symptomatic, may require hospitalization. Some of them may not recover. • Fully asymptomatic people, individuals in the incubation phase, and symptomatic patients can all shed and spread the virus. • The virus is transmitted through direct or indirect contact with droplets (milli or micro) that an infected person releases when she coughs, sneezes, sings, talks, or breathes out. • Avoiding crowded spaces, the use of face masks, physical distancing, and frequent washing of hands with soap can all reduce risk of infection.

Note: Source of the image used in the background of the article title: https://commons.wikimedia.org/wiki/File:Sneeze.JPG. Credits: James Gathany, CDC Public Health Image library ID 11162, Wikimedia Commons. License: CC-BY.

N. D. Hari Dass is a retired theoretical physicist. He was formerly a professor at the Tata Institute of Fundamental Research (TIFR), Hyderabad, and The Institute of Mathematical Sciences (IMSc), Chennai. He is deeply committed to science outreach of various kinds. Shantala Hari Dass is the Associate Director of IndiaBioscience, Bangalore. Kamal Lodaya is a retired professor in theoretical computer science from The Institute of Mathematical Sciences (IMSc), Chennai. He is actively involved in science communication. R. V. Vandana is a postdoctoral researcher at the Max Planck Institute for Evolutionary Biology, Ploen, Germany.

34 — Rediscovering School Science | Oct 2020 SNIPPETS

— Rediscovering School Science | Oct 2020 35 SNIPPETS

CAN THE SARS-CoV-2 INFECTION SPREAD THROUGH THE USE OF AIR CONDITIONING?

According to a recent study, a SARS-CoV-2 infected person China shows transmission of the SARS-CoV-2 virus from releases about 1000 droplets (containing viral particles) a single presymptomatic patient to not just people on within a minute of loud speech. These droplets can remain the same table, but also those on the neighboring tables. airborne for at least 8 minutes. Thus, despite physical Even though samples from the A/C filter were negative distancing, the SARS-CoV-2 infection may spread if people for the virus, the airflow is believed to have facilitated share the same air for prolonged periods in confined places transmission across tables. Another study in a call centre with poor ventilation (i.e., without access to fresh air). in South Korea showed clustered infections on one floor This also means that centrally air-conditioned rooms may of the centrally air-conditioned office. Although there is increase risk of infection. This is because A/Cs circulate no experimental evidence on the movement of droplets air back into the same space repeatedly, thereby also containing the SARS-CoV-2 virus through air filtration circulating any contaminants (like virus particles) in the air. systems and A/C ducts, these and other studies point to the possibility of the virus circulating in confined air- Many recent reports in centralized air-conditioned conditioned spaces with poor natural ventilation. environments indirectly point towards this mode of transmission. For example, a study in a restaurant in Until proven otherwise, it may be safer to avoid visiting crowded public places with central A/C and poor ventilation, like supermarkets, malls, offices, trains, and restaurants. For domestic use, A/Cs are unlikely to increase the chance of infection because people in a household share their living space, and are in close contact anyway. Regardless, natural and frequent ventilation is recommended. If a family member gets infected, when possible, they should be isolated in a separate room that does not share an A/C with other rooms in the house. In fact, the MoHFW, Government of India guidelines suggest Source URL: https://www.needpix.com/photo/1214884/window-open- that for an infected person, natural ventilation (through two-old-pane-facade-house-former. open windows) is preferable to an A/C.

Notes: 1. This response was first published on the Indian Scientists’ Response to CoViD-19 (ISRC) website. 2. Source of the image used in the background of the article title: https://pixabay.com/illustrations/air-conditioner-ac-cool-cooling-4204637/. Credits: mstlion, Pixabay. License: CC-0.

36 — Rediscovering School Science | Oct 2020 OUR RESPONSE

IMMUNE RESPONSE TO COVID-19 SATYAJIT RATH

How does our body respond ur body responds to any That said, the body has three major direct to infection? Can it limit infection — viral, bacterial, ways of limiting a virus infection. In one infection by a virus? How Ofungal, whatever — in ways antiviral response, the body sends signals is inflammation different that tend to restrict its spread. In to its own cells to make life difficult for other words, these responses tend any virus entering them. Examples of from an adaptive response? to ‘quarantine’ the infection in such signals include interferon-alpha What factors can weaken ‘containment zones’. This category and interferon-beta that are being tried our immune response? of responses is what we refer to as as treatments for COVID-19. Another What do ‘cytokine storms’ inflammation. In addition, the human response is for the body to produce have to do with COVID-19? body also has responses that are proteins, called antibodies, that stick How do we develop herd directly antiviral. to the exact part of the virus surface immunity? through which the virus sticks to body cells. Such antibody-coated viruses Antiviral responses cannot get into cells to infect them. This It is useful to think about interactions is what treatments like plasma therapy between the human body and the or monoclonal antibody therapy hope viruses infecting it in ways that are to achieve. It is also what we hope to more nuanced than a ‘fight’. Many a generate with the SARS-CoV-2 vaccines time, the body simply tolerates viruses. that are in the pipeline. A third way the At other times, viruses simply ‘ride body limits virus infection is through along’ with cells of the body rather ‘killer’ cells. Killer cells can identify and than damaging them. At yet other kill recently infected body cells before the times, the body’s response does not production of new virus copies in them really ‘fight’ the virus infection. can be completed.

— Rediscovering School Science | Oct 2020 37 Antiviral responses involving antibodies repertoire capable of recognising the not. Similarly, we do not know how to and killer cells are called adaptive virus, then adaptive responses also kick predict how long the expanded adaptive responses. They ‘look’ at the virus in quickly (within minutes to hours). This repertoire against any given infection that has come in, then ‘search’ and is why we are better protected against will last in the body. This means that for ‘find’ antibody-producing and killer reinfection by the same virus (or by every new pathogen we meet, and for cells in their own repertoires that can vaccination). Keep in mind that we are every new vaccine we want to make, match bits on the surface of the virus protected by these immune responses we have to learn these two things or a virus infected cell. This part of even when we meet an infection for afresh, through trial and error. This is the body’s repertoire of cells is then the first time. It is just that having an why we are, and should be, so uncertain expanded and brought into operation, expanded adaptive repertoire gives about SARS-CoV-2 and COVID-19; either as antibodies or as killer cells. The quicker and better protection. However, we are still learning new things about expanded repertoire remains in the body these expanded adaptive repertoires them. This is also why ‘designing’ and even after the virus is dealt with. can be lost over time. If this happens, ‘making’ vaccines against SARS-CoV-2 then we become as susceptible to that is uncertain and time-consuming, why Adaptive responses particular infection as we would be if there are over a hundred different we had never met the virus before (or Everyone has inflammatory and efforts going on the world over, and had not been vaccinated against it). interferon responses to viral infection. why most of them stand equal chances These responses come into operation Here is what we do not know. We do not of success (or failure). immediately (within minutes to know how to predict which particular Recent findings suggest that antibody hours) after infection. Adaptive bits of the virus the body will make the responses against SARS-CoV-2 may be antiviral responses are perhaps more most antibodies against. A paradoxical modest, and may last for only a few effective, but take a little time to kick disadvantage of having a large adaptive weeks or months, especially in people in. Especially if we have no previous repertoire is that there will be matches without any symptoms or with only exposure to anything that looks like with most parts of the virus particle. mild symptoms. We should keep this the virus (the virus itself, a very very In other words, the adaptive response possibility in mind when we think similar virus, or a mimic vaccine). This will make antibodies against the virus about how we, as a society, are going is because it takes time (usually only a surface and its interior. Only those to respond to the disease over the long couple of days, but sometimes a little antibodies that stick to the specific term (until there are reasonably effective more than that) to expand the body’s patches on the virus surface through vaccines available to everyone!). initial repertoire of matching antibody- which the virus sticks to body cells will producing or killer cells. On the other provide protection (see Fig. 1). This hand, if the virus enters a body that means that we can never be sure if we Factors affecting our already has an expanded adaptive will make lots of useful antibodies or immune response Most of us have fairly good immune responses. If we did not, we would have had lots of other infections since childhood, and would most likely have been in and out of hospitals! In fact, this is what happens in the case of people who have been undergoing chemotherapy for cancer. As a side- effect of this therapy, their immune responses are poor enough to make them more likely to have severe COVID-19 illness. A little differently, any ongoing inflammation can affect containment and antiviral responses enough to increase our chances of developing severe COVID-19 illness. This is what happens in the case of the elderly, those with Fig. 1. Antibodies offer protection when they stick to the exact part of the virus surface through which the virus sticks to body cells. obesity, type 2 diabetes, heart disease Credits: Adapted from an image by Erlangen, Germany, on Siemens Healthineers. URL: https://www. or hypertension, as well as those with siemens-healthineers.com/en-in/press-room/press-releases/covid-19-antibody-phe.html. chronic kidney, liver, or lung diseases.

38 — Rediscovering School Science | Oct 2020 Cytokine storms body. If the virus is lucky (!), these copies be smaller than the one before it, and will be thrown out of the body somehow the infection will simply die down. The The inflammatory immune response greater than one this number is, the tends to provide containment of any (usually via bodily fluids). On making more rapid the spread of the infection incoming pathogen to the site where appropriate contact with other people, in the community. However, this number it is first encountered by the body. The these copies can establish infection. also depends on the immunity of people body uses locally made chemical signals, So, by the time the first person to be exposed to an infected person. People called cytokines, to create ‘micro- infected eliminates the virus from their who have met the virus earlier, and have containment’ zones. Of course, the body, the next round of people will be expanded their adaptive repertoire in cytokines leak a bit beyond, but in such making and transmitting copies of it. response are adaptive immune. Such small amounts that they will have no A crucial factor for the ‘success’ of the effect outside these zones. people do not get infected. If most of virus is the number of people who get the people an infected person comes This can backfire when we are exposed successfully infected from one infected into contact with are adaptive immune, to very high doses of the virus. This is person. If this number (called ‘R’) is less then it reduces the efficiency with which common in caregivers, nurses, doctors, than one, then each cycle of spread will the virus spreads. This will also happen and other healthcare workers with prolonged exposure to infected people (or those who spend hours in a crowded and closed room with air-conditioning). In such cases, the virus enters our body through many different points in the airways. This can also backfire if our early immune responses are somewhat off-kilter and slow to get off and running. This is seen in people undergoing chemotherapy for cancer, or with ongoing inflammation in the body. In such cases, even a small dose of the virus will expand and spread to a number of locations in the body by the time the immune response is activated. In both cases, all the immune response can, and will, try to do is achieve micro- containment at all locations. The trouble is that cytokines will leak out from each of these ‘wannabe’ micro-containment zones. All the leaking chemicals add up to a lot, and begin to have effects outside the localised zones, all over the body. The result is that the entire body attempts to become a huge containment zone, like an entire country shut down for months in a policed ‘lockdown’. This Fig. 2. Herd immunity is a natural consequence of a critical proportion of people in a community becoming adaptive immune to a pathogen. To start with, no one is immune accumulation of cytokines all over the to novel pathogens like SARS-CoV-2. The infection spreads rapidly through the body is referred to as a cytokine storm, community. Over time, two categories of people become adaptive immune to it — those and results in severe illness. who recover from the infection, and those who receive a vaccine against it. Research suggests that protection from the adaptive immune response in COVID-19 infected people may last for only a few weeks or months. As of now, there is no proven vaccine Herd immunity against the virus. If enough people in a community become adaptive immune to the Let us think about how a virus spreads pathogen, it reduces the chances of those who are less immune to it from coming into (or is ‘transmitted’) in a community. Let’s contact with an infected person. This reduces the spread of infection. Estimates suggest that this is likely to happen with SARS-CoV-2 when 50-80% of the population becomes say one person is exposed to the virus (in adaptive immune to it. some remote jungle, let us assume!) and Credits: Tkarcher, Wikimedia Commons. URL: https://commons.wikimedia.org/wiki/File:Herd_ is infected. Till they deal with the virus, immunity.svg. License: CC-BY-SA. new virus copies will get made in their

— Rediscovering School Science | Oct 2020 39 if a large proportion of people become a policy strategy that either Sweden It will be evident that for a stable adaptive immune because they are or Mister Boris Johnson designed (and, situation of herd immunity to exposed to a reasonably effective vaccine of course, relying on it as a ‘strategy’ is come about, virus infection must (rather than actually getting infected). quite silly in both cases). result in a good protective adaptive So, if a large enough proportion of What proportion of people must be immune response, and this response people in a community are adaptive adaptive immune to SARS-CoV-2 (antibodies, for example) must not immune to the virus, it is likely that the for this point of herd immunity to disappear quickly. For SARS-CoV-2 spread of the virus will essentially come be reached? We don’t know for sure virus, while the first condition appears to a halt (see Fig. 2). This situation is — the percentage varies based on a to be fulfilled in a fair proportion of called herd immunity. But, perhaps, we number of factors specific to individual infected people, there seems to be should call it ‘community immunity’, infections and microbes. However, some uncertainty about how long which is both rhyming and accurate? numbers between 50-80% have been antibodies last. So it is possible that brought up. As of now, the highest herd immunity for SARS-CoV-2 will Parting thoughts recorded proportion of people with be somewhat unstable. To stabilise As we can see, most infections will, in adaptive immunity to SARS-CoV-2 is the situation, it is likely that we will all likelihood, reach the point of herd about 20%. Clearly, SARS-CoV-2 herd depend (more than we had originally immunity sooner or later. So herd immunity has not developed in any thought) on the vaccines that will immunity is just a natural outcome, not part of the world yet. begin to come out next year.

Key takeaways

• The human body uses inflammation and antiviral responses to protect us from a virus infection. • Inflammation restricts spread of infection by using cytokines to quarantine it in containment zones. • Antiviral responses limit infection in three major ways — signalling cells to make virus entry difficult, producing antibodies that prevent the virus from attaching to cells, and recruiting killer cells to identify and kill infected cells. • Since antiviral responses involving antibodies and killer cells are ‘adaptive’, they may take time to kick in. • Antibody responses against SARS-CoV-2 may be modest, and may last for only a few weeks to months. • People undergoing chemotherapy for cancer, and with ongoing inflammation are more prone to severe COVID-19 illness. • Two factors — exposure to high doses of virus, and compromised immunity — can lead to cytokine storms that result in severe illness. • Herd immunity is the natural consequence of a large number of people becoming adaptive immune because of prior exposure to the virus, or effective vaccination.

Note: Source of the image used in the background of the article title: https://www.flickr.com/photos/niaid/49680384281/in/photostream/. Credits: The National Institute of Allergy and Infectious Diseases, US. License: CC-BY.

40 — Rediscovering School Science | Oct 2020 SNIPPETS

RESOURCES ON COVID-19

The Indian scientific community has developed some Contents: COVID-Gyan publishes articles, videos, podcasts, resources that are based on our current scientific infographics, and do-it-yourself/tutorials in 12 Indian understanding of the pandemic. Available in multiple languages. The topics include current research, FAQs, and Indian languages and free of cost, these resources have common myths related to COVID-19 and well-being. been generated or compiled to increase public awareness about the pandemic, and fight misinformation. Here are Indian Scientists’ Response to COVID-19 some examples. (ISRC) (www.indscicov.in) IndiaBioscience (www.indiabioscience.org) About: ISRC started as a voluntary effort by a group About: IndiaBioscience is a unique of Indian scientists in the program that brings together wake of the pandemic. It different life science professionals, now comprises more than including researchers, educators, 500 volunteers including students, and policy makers from scientists, doctors, public health researchers, engineers, across India on a common platform. It showcases Indian technologists, science communicators, journalists, and a biological research and opportunities, runs various skill- number of students. building programs, generates and curates resources, and enables discussions on various policy-related matters in Contents: ISRC provides several infographics, snippets, and the country. It is primarily funded by the Department of videos on myths and FAQs associated with COVID-19, and Biotechnology (DBT), Government of India. It has also on well-being in the time of a pandemic. The content is received funding for specific projects from the Ministry of available in 19 Indian languages. Education and DBT/Wellcome Trust India Alliance. DBT/Wellcome Trust India Alliance Coverage on COVID-19: IndiaBioscience generates and curates articles, podcasts, videos, and infographics related (India Alliance) (www.indiaalliance.org) to COVID-19. The topics include FAQs, common myths, About: DBT/Wellcome current research, and maintaining well-being during the Trust India Alliance pandemic. Most of the content is in English, but some of it (India Alliance) is an is also available in Hindi and Kannada. independent public charity that funds basic biomedical, clinical, and public COVID-Gyan (www.covid-gyan.in) health research in India. It is funded by the Department of Biotechnology (DBT), Government of India, and the About: This website serves as a hub of Wellcome Trust, United Kingdom. resources based on the best available scientific understanding of the COVID-19 Coverage on COVID-19: The website provides several pandemic. It was created by some of the infographics, articles, webinars with experts, and other top public-supported research institutes resources on the pandemic, developed by India Alliance and and associated programs in India. Participating institutions its grantees. The topics covered include the origin, spread, include Tata Institute of Fundamental Research (TIFR) and and preventive measures against COVID-19, research by its centres, Indian Institute of Science (IISc), Tata Memorial grantees, and self-care tips. Some of the resources are Centre (TMC), Vigyan Prasar, IndiaBioscience, and InStem. available in several Indian languages.

Vijeta Raghuram works as the Program Manager, Science Education at IndiaBioscience. She has a PhD in biophysics from the Centre for Cellular and Molecular Biology (CCMB), Hyderabad. She can be contacted at: [email protected].

— Rediscovering School Science | Oct 2020 41 SNIPPETS

9 THINGS YOU CAN DO TO MANAGE YOUR COVID-19 SYMPTOMS AT HOME

Stay home from work and school. And stay away from other public places. If you 1 must go out, avoid using any kind of public transportation, ridesharing, or taxis.

Monitor your symptoms carefully. If your symptoms get worse, call your healthcare 2 provider immediately.

3 Get rest and stay hydrated

If you have a medical appointment, call the healthcare provider ahead of time and 4 tell them that you have or may have COVID-19.

5 Cover your coughs and sneezes

Wash your hands often with soap and water for at least 20 seconds or clean your 6 hands with an alcohol-based hand sanitizer that contains at least 60% alcohol.

As much as possible, stay in a specific room, and away from other people in your 7 home. Also, you should use a separate bathroom, if available. If you need to be around other people in or outside of the home, wear a cloth face covering.

Avoid sharing personal items with other people in your household, like dishes, 8 towels, and bedding.

Clean all surfaces that are touched often, like counters, tabletops, and doorknobs. 9 Use household cleaning sprays or wipes according to the label instructions.

The Centers for Disease Control and Prevention is a national public health institute in the United States. To access a poster with this information, please visit: https://www.cdc.gov/coronavirus/2019-ncov/if-you-are-sick/steps-when-sick.html.

42 — Rediscovering School Science | Oct 2020 OUR RESPONSE

SARS-CoV-2 INFECTION: PROTECTION & PREVENTION ASHA MARY ABRAHAM

How do vaccines protect he world has seen numerous cases from around the world with about us from infection? How pandemics in the course of 900,000 reported deaths.6 How do we are they developed? How Thuman history. One of the protect ourselves and prevent infection? quickly can a vaccine most severe ones in recent history was the influenza pandemic of 1918 against COVID-19 be Protection from SARS- that infected a third of the world and CoV-2 infection made widely available for killed between 20-50 million people.1 use? What behavioural Subsequent influenza outbreaks One of the most important methods changes can help prevent that occurred in 1957 and 1968 of decreasing the burden of infection? Do our general killed 2 million and 1 million people infectious diseases around the world is immunization. Immunization is a health and immunity respectively.2 The HIV/AIDS pandemic process by which we develop protection impact our risk of that began in 1981 has killed about 32 3 or immunity to the pathogen or developing severe disease? million people worldwide. The Severe Acute Respiratory Syndrome Coronavirus infectious agent causing a disease (SARS-CoV) spread from 2002 to 2003, through the administration of a vaccine. causing about 813 deaths, while the Vaccines are administered by injection, H1N1 influenza spread in 2009 led to orally, or nasally via aerosol. about 575,000 deaths.4 More recently, How does a vaccine protect us? It the Middle East Respiratory Syndrome triggers antibody production and Coronavirus (MERS-CoV), which was first cell-mediated immunity against an identified in Saudi Arabia, has caused infectious agent or pathogen inside the 858 deaths since 2012.5 Currently, the body. This is achieved by exposing our world is in the grip of the COVID-19 body to a killed or weakened pathogen, pandemic caused by the SARS-CoV-2 a toxin it produces, or a component virus. From its beginnings in December (like a surface protein), called antigen, 2019 to mid-September 2020, there are that can trigger such a response against over 29 million confirmed COVID-19 the live, infectious pathogen. Often,

— Rediscovering School Science | Oct 2020 43 adjuvants (like aluminum salts) are used interest, which are delivered by direct z Phase II trials are aimed at to increase the immune response that injection into the individual. Some DNA determining safety, immunogenicity, the vaccine triggers. Which of these are vaccines against respiratory viruses are immunization schedule, and dose size in used in vaccines against viruses? Some delivered nasally through aerosols, while a few hundred individuals, and antiviral vaccines are in the form of others are delivered in edible forms. z Phase III trials where thousands or an inactivated virus. Vaccines against In contrast, RNA vaccines, delivered in tens of thousands of test subjects are polio, rabies, influenza, and Japanese lipid nanoparticles, induce antibody vaccinated to continue determining encephalitis are examples of such production by coding for proteins that the safety and effectiveness of the vaccines that have led to the eradication resemble those of the pathogen. candidate vaccine, perform regulatory of disease. Other antiviral vaccines review and approval, manufacturing, As with any medical intervention, the can be in the form of live attenuated and quality control.7 general cycle of vaccine development viruses. Examples include the oral polio and their routine approval for use The normal route to vaccine approval vaccine, as well as vaccines against involve multiple stages (see Fig. 1). The takes at least two decades. But these measles, mumps, rubella, yellow fever, first stage, called theexploratory stage, are not normal times. Over the past few influenza, and rotavirus. Live attenuated months, many vaccine companies have viral vaccines have low pathogenic is used to identify natural or synthetic antigens that may prevent disease. In stepped up to the task of developing ability but retain their ability to induce an anti-COVID-19 vaccine in a matter immunity. Yet other vaccines may be in the second stage, called the preclinical stage, cell or tissue culture systems and of months rather than decades. For the form of a component of the virus example, Oxford University has tied up animals are used to determine if the that confers immunity. For example, with the Serum Institute of India and vaccine candidate produces immunity virus-like particles (empty protein shells identified a vaccine candidate that has or proves harmful. In the third stage, of viruses) have also been used to make elicited a protective immune response called the clinical development stage, vaccines against the human papilloma- in early trials. Meanwhile, Bharath institutions that receive approval from virus, rotavirus, and influenza virus. Biotech's indigenously produced vaccine, Newer vaccines, like the recombinant regulatory bodies conduct three phases Covaxin, has shown an encouraging hepatitis B vaccine, have the viral gene of clinical trials: safety profile in Phase I trials. The of interest cloned and expressed in yeast z Phase I trials are aimed at possibility of using a Controlled cells to allow easy production. DNA determining safety of the vaccine in a Human Infection Model (CHIM) is also vaccines can be in the form of genes of small group of volunteers being explored in this context. In this

Fig. 1. How is a new vaccine developed, approved, and manufactured? Credits: Adapted from an image by the U.S. Government Accountability Office from Washington, DC, United States, Wikimedia Commons. URL: https:// en.wikipedia.org/wiki/File:The_vaccine_development_process_typically_takes_10_to_15_years_under_a_traditional_timeline._Multiple_regulatory_pathways,_ such_as_Emergency_Use_Authorization,_can_be_used_to_facilitate_bringing_a_vaccine_for_COVID-19_to_(49948301848).jpg. License: CC-BY.

44 — Rediscovering School Science | Oct 2020 model, healthy participants consent to but can shed the virus and infect others. long the virus stays active on these being deliberately exposed to a well- For example, in a study conducted in surfaces depends on many factors. For characterized and weakened form of China, a small sample of asymptomatic example, SARS-CoV-2 is sensitive to a pathogen under highly controlled individuals were found to show lower ultraviolet rays and heat, but can resist conditions. This can help us gather more antibody levels and a weaker immune the cold (even temperatures below robust information on pathogenesis, response. However, they were able to shed 0°C). The phospholipid envelope of the potential vaccine candidates, duration the virus over a longer duration of time.10 virus can be effectively inactivated of immunity post-vaccination, and Who would we be most likely to transmit by solvents that dissolve lipids. These the nature of protection in a healthy the infection to? Spread is most likely include ether (75%), ethanol, chlorine- population.8 The key challenge in vaccine to occur among close contacts (family, containing disinfectant, peroxyacetic development for COVID-19 is to achieve health care workers) at around 1.8 m acid, and chloroform (except for speed without compromising on the distance.9 chlorhexidine).11 Soap can also regulatory aspects built into the process effectively inactivate the lipid layer. Simple behavioral changes can help to ensure safety, efficacy, and quality. This is why washing hands often with prevent infection through: soap and water for at least 20 seconds Prevention through z Direct contact with droplets and (before touching one’s face, eating, aerosols: Keeping a physical distance of preparing food; and after using the behavioral change up to 2 m (or 6 feet) from other people in restroom, coughing, sneezing, blowing That the SARS-CoV-2 infection is highly public spaces is an important preventive one’s nose, caring for the sick, and transmissible is evident by its current measure. This can help protect us from handling a face mask) is recommended. spread. This infection spreads through close contact with infected people, and If soap and water are not available, respiratory droplets released when protect others from the risk of infection then a hand sanitizer with at least an infected person coughs, sneezes, by direct contact with droplets released 60% alcohol must be used.11 Surfaces speaks loudly, or sings. Some of these by us. Covering the mouth and nose with that are frequently touched should droplets land on physical surfaces. An a cloth mask in public places is crucial, be cleaned and disinfected daily with uninfected person catches the infection particularly when physical distancing household disinfectants.12 when they come into direct or indirect is difficult to maintain. However, it’s Some categories of individuals are at (touching a surface contaminated with important to keep in mind that a mask is higher risk for severe COVID-19 illness. the virus, and then touching one’s nose not a substitute for physical distancing. Risk factors in these categories include or mouth) contact with these droplets. Other important ways of preventing age (with the highest risk in individuals It is now believed that the infection can infection include the practice of always above 85 years) and underlying also spread by inhalation of aerosols covering the mouth and nose with a medical conditions (like cancer, chronic that remain suspended in the air for a tissue when coughing or sneezing. If this kidney disease, chronic obstructive few minutes to a few hours. The risk is not available or possible, the inside pulmonary disease, obesity, serious of transmission increases in closed of the elbow may be used instead. If heart conditions, and Type 2 diabetes spaces. For example, a study showed a tissue is used, it must be disposed of mellitus). Other individuals who might the presence of the virus in the air up immediately after use, and our hands be at risk for severe COVID-19 include to 4 m away from infected patients in a must be washed well with soap and those with moderate to severe asthma, hospital. While this is twice the distance water. This will help prevent spread of cerebrovascular diseases, high blood recommended for physical distancing any viruses on our hands to any surface pressure, immunocompromised states measures, the researchers involved in or person one encounters next. (from transplants, immune deficiencies, this study also cautioned that the small z Indirect contact with fomites or HIV, steroid use), dementia, pregnancy, number of viruses found at this distance contaminated surfaces: Like other liver disease, lung fibrosis, smokers, may not necessarily be infectious.9 coronaviruses, SARS-CoV-2 is an and Type 1 diabetes mellitus.13 For Not everyone who is infected shows enveloped RNA virus. It has been found individuals with these risk factors, the clearly identifiable symptoms of disease to remain active on metal and plastic best way to prevent COVID-19 is to immediately after being infected. Once surfaces for up to three days, and on avoid contact with infected individuals. it enters the body, SARS-CoV-2 can go soft surfaces (like carpets and curtains) This is particularly important till COVID- through an incubation period that ranges for shorter durations. For example, one 19-specific drugs and vaccines become from 1-14 days. It usually lasts 3-7 days, study showed that the floors, computer widely available. People with mild but could extend to 24 days in some surfaces, handrails, door knobs, and symptoms who are otherwise healthy cases. During this presymptomatic stage, waste bins in Intensive Care Units are advised to manage their symptoms people continue to shed the virus. Other (ICU’s) can be contaminated with the at home so that hospital facilities are infected people show no symptoms at all, virus shed by an infected person. How available for more severely ill patients.

— Rediscovering School Science | Oct 2020 45 Parting thoughts Maintaining a healthy lifestyle (eating However, some supplements are essential and vitamin B complex. Other less a balanced diet, getting adequate sleep, to proper functioning of the immune rigorously studied supplements are being physically active, and refraining system, and have been shown in various garlic and curcumin (found in turmeric). from smoking) is important in keeping well-conducted studies to lower the risk However, no supplement is currently the immune system healthy to reduce and/or duration of respiratory infections. known to actually protect against episodes and duration of disease. These include vitamin D, zinc, vitamin C COVID-19 per se.

Key takeaways

• Immunization is one of the most important methods of decreasing the burden of infectious diseases around the world. • Vaccines protect us by triggering antibody production and cell-mediated immunity against an infectious agent or pathogen that is subsequently encountered inside the body. • The general cycle of vaccine development involves three stages — exploratory, preclinical, and clinical development. • The clinical development stage involves three phases of clinical trials to test the safety, efficacy, and quality of the vaccine. • Many companies have risen to the challenge of developing a vaccine for COVID-19 through processes that combine speed with safety, efficacy, and quality. • Infection can be prevented through simple behavioural changes like physical distancing, the use of face masks, frequent washing of hands with soap and water, as well as disinfecting frequently used surfaces. • Maintaining a healthy lifestyle is important in keeping the immune system healthy enough to reduce episodes and duration of disease.

Note: Source of the image used in the background of the article title: https://media.istockphoto.com/photos/clinical-trial-vaccine-covid19-coronavirus-in-vial- with-syringe-on-picture-id1215846334. Credits: Bill Oxford.

References: 1. Centers for Disease Control and Prevention (US). 1918 Pandemic (H1N1 8. Deming ME, Michael NL, Robb M, Cohen MS, Neuzil KM. Accelerating virus). Retrieved on Sep 3, 2020. URL: https://www.cdc.gov/flu/pandemic- development of SARS-CoV-2 vaccines – The role for controlled human resources/1918-pandemic-h1n1.html. infection models. N Engl J Med 2020. URL: https://www.nejm.org/doi/ 2. Centers for Disease Control and Prevention (US). 1957-1958 Pandemic full/10.1056/NEJMp2020076. (H2N2 virus). Retrieved on Sep 3, 2020. URL: https://www.cdc.gov/flu/ 9. Cascella M, Rajnik M, Cuomo A, et al. Features, Evaluation and Treatment pandemic-resources/1957-1958-pandemic.html. Coronavirus (COVID-19) [Updated 2020 Jul 4]. In: StatPearls [Internet]. 3. World Health Organization (Switzerland). Global Health Observatory (GHO) Treasure Island (FL): StatPearls Publishing; 2020 Jan-. Available from: data — HIV/AIDS. Retrieved on Sep 3, 2020. URL: https://www.who.int/gho/ https://www.ncbi.nlm.nih.gov/books/NBK554776/. hiv/en/. 10. Long, Q., Tang, X., Shi, Q. et al. Clinical and immunological assessment 4. Centers for Disease Control and Prevention (US). 2009 H1N1 Pandemic of asymptomatic SARS-CoV-2 infections. Nat Med (2020). https://doi. (H1N1pdm09 virus). Retrieved on Sep 3, 2020. URL: https://www.cdc.gov/ org/10.1038/s41591-020-0965-6. flu/pandemic-resources/2009-h1n1-pandemic.html. 11. Jing JLJ, Pei Yi T, Bose RJC, McCarthy JR, Tharmalingam N, Madheswaran 5. World Health Organization (Switzerland). Middle East respiratory syndrome T. Hand Sanitizers: A Review on Formulation Aspects, Adverse Effects, and coronavirus (MERS-CoV). Retrieved on Sep 3, 2020. URL: https://www.who. Regulations. Int J Environ Res Public Health. 2020;17(9):3326. Published int/emergencies/mers-cov/en/. 2020 May 11. doi:10.3390/ijerph17093326. 6. World Health Organization (Switzerland). Coronavirus disease (COVID-19) 12. Centers for Disease Control and Prevention (US). How to Protect Weekly Epidemiological Update and Weekly Operational Update. Retrieved Yourself & Others. Retrieved on Sep 3, 2020. URL: https://www.cdc.gov/ on Sep 3, 2020. URL: https://www.who.int/emergencies/diseases/novel- coronavirus/2019-ncov/prevent-getting-sick/prevention.html. coronavirus-2019/situation-reports. 13. Centers for Disease Control and Prevention (US). People with Certain 7. Centers for Disease Control and Prevention (US). Vaccine Testing and the Medical Conditions. Retrieved on Sep 3, 2020. URL: https://www.cdc.gov/ Approval Process. Retrieved on Sep 3, 2020. URL: https://www.cdc.gov/ coronavirus/2019-ncov/need-extra-precautions/people-with-medical- vaccines/basics/test-approve.html. conditions.html.

Asha Mary Abraham is a Professor and a former Head of the Department of Clinical Virology at the Christian Medical College (CMC) Vellore, Tamil Nadu.

46 — Rediscovering School Science | Oct 2020 SNIPPETS KALONJI, HOT TEA, GARLIC & COVID-19

Will consuming Kalonji seeds, which are rich in hydroxychloroquine, prevent COVID-19? There is no evidence that Kalonji seeds are rich in hydroxychloroquine or chloroquine. They are rich in an unrelated compound called thymoquinone, which has not been tested or approved for the treatment of COVID-19. There is no evidence that thymoquinone is converted to hydroxychloroquine or chloroquine in the human body. There is also no indication that thymoquinone works like hydroxychloroquine or chloroquine. protein from SARS-CoV, another coronavirus. But this was never tested on living cells, or in patients infected with SARS-CoV-2. Overall, there is no evidence suggesting that drinking tea can destroy SARS-CoV-2, or prevent COVID-19. However, hot tea may help us feel better by providing temporary relief from symptoms like blocked sinuses and a sore throat.

Will consuming garlic help prevent or recover from COVID-19? Can drinking hot tea prevent Both prevention and recovery from COVID-19 require COVID-19? virus-specific, active immunity. When the SARS-CoV-2 virus infects a person for the first time, an existing army of o The normal human body temperature is 37 C, and most cells, ready to fight all kinds of invading organisms, springs hot liquids that we drink are typically at a temperature into action (the body’s first line of defense or innate o of 57.8 C. Once a virus has already entered our lungs, it is immunity). Sometimes the virus is able to bypass this protected from high temperatures. Even if the virus is in defense and keep multiplying. Over the next few days (or our throat, we would need to maintain a body temperature weeks), immune cells learn and mount an active response, above 56oC (138.2 deg F) for about 30 minutes to inactivate generating antibodies that act like guided missiles targeted it. This is impossible to do by drinking hot liquids, and would specifically at the virus. Patients who have recovered from be dangerous if attempted by other means. COVID-19 have these specific antibodies. The only way to Although tea is rich in compounds such as flavins, there generate this specific antibody-driven response is through is no evidence for their antiviral properties in the human exposure to the virus, or by vaccination with either an body. One lab study (2005) showed that Theaflavin, a inactivated virus, or proteins that mimic part(s) of the compound found in Pu’er (a fermented tea from Yunan virus. There is no evidence to suggest that consumption of province) and Black tea, can inhibit the activity of a garlic contributes to such a response.

— Rediscovering School Science | Oct 2020 47 have other methodological issues. For example, although many trials have been conducted to test the effect of garlic on common cold, an independent assessment found that only one trial was well controlled; and even this study administered a dosage equivalent to as many as 10-30 cloves of garlic per person per day. Also, studies on the efficacy of purified compounds or garlic extracts cannot easily be generalised to the dietary consumption of garlic. In summary, the evidence suggesting that garlic can improve immune function is weak.

Some studies suggest that some compounds found in garlic By all means, one may consume garlic to help maintain might benefit general health, and improve the non-specific, good health, which is associated with good overall innate component of the immune response. However, immunity. However, there is no evidence proving that these most such studies are poorly controlled in terms of dose general healthy choices are sufficient to cure or build composition and amount, efficacy, placebos, sample size, or preventive immunity against COVID-19.

Notes: 1. These responses were first published on the Indian Scientists’ Response to CoViD-19 (ISRC) website. 2. Source of the image used in the background of the article title: https://pixabay.com/photos/coronavirus-corona-virus-covid-19-4958989/. Credits: thiagolazarino, Pixabay. License: CC-0.

SNIPPETS WILL SPRAYING BLEACH ON SOMEONE WHO MIGHT BE INFECTED DESTROY SARS-CoV-2?

Bleach (sodium or calcium hypochlorite) is a common, on people or groups of people (in disinfection tunnels, for inexpensive, generally safe, and widely used disinfectant. example) is not recommended. This is because using bleach It can be used to disinfect virus-contaminated external to spray the exterior of the body of a person infected with surfaces. Very dilute solutions of bleach (0.05% SARS-CoV-2 does not destroy the virus inside their bodies. concentration) can be used to disinfect hands when soap/ Instead, bleach solution, even as dilute as 0.05%, can cause inflammation of the skin (dermatitis) and asthma. At water are not available. concentrations higher than 1%, this solution can irritate However, spraying it (or any other chemical disinfectant) the eyes, throat, and skin.

Notes: 1. This response was first published on the Indian Scientists’ Response to CoViD-19 (ISRC) website. 2. Source of the image used in the background of the article title: https://pixabay.com/photos/coronavirus-corona-virus-covid-19-4958989/. Credits: thiagolazarino, Pixabay. License: CC-0.

48 — Rediscovering School Science | Oct 2020 OUR RESPONSE

TESTING FOR COVID-19 YASMIN JAYATHIRTHA

How do we detect COVID-19 OVID-19 is caused by the virus 100 samples tested (1 false negative). infection? What kind of SARS-CoV-2, which belongs Similarly, a test with a specificity of 95% samples are needed to test Cto a family of coronaviruses will incorrectly identify the presence of the antigen or antibody in 5 of every infection? What is the that infect the respiratory tract (see Fig. 1). It can be diagnosed by testing 100 samples (5 false positives). likelihood of a test result for the presence of genetic material being inaccurate? How do (molecular tests) or proteins (antigen Table I. What are false negatives and false positives? molecular and antigen tests tests) specific to the virus, or the body’s work? When are antibody response (antibody test) to infection Has COVID-19 COVID-19 free tests effective? Which tests (see Fig. 2). would be most effective Tests positive True False For any test to be useful, it must be for contact tracing, and for COVID-19 positive positive specific, detecting only the element which for population-wide Tests negative False True (molecule, antigen or antibody) of for COVID-19 negative negative screening? interest. It should also be sensitive, giving positive results even when the Molecular tests relevant element is present at low Designed to detect the presence of concentrations in the sample. In theory, the genetic material of SARS-CoV-2 a perfect test would have a specificity in a swab sample, these tests are based (or true negative rate) and sensitivity on a method called Reverse (or true positive rate) of 100% (see Transcription Polymerase Chain Table I). In practice, there are no perfect Reaction or RT-PCR (see Box 1). With a tests. A test with a sensitivity of 99% sensitivity and specificity that is close will miss the presence of the antigen to 100%, molecular tests set the gold or antibody of interest in 1 out of standard in COVID-19 testing.

— Rediscovering School Science | Oct 2020 49 Box 1. How do molecular tests work? In the first step of a molecular test, all the RNA in a swab sample (cellular and virus) is reverse transcribed into complementary DNA molecules. In the second step, only DNA sequences specific to the virus are amplified through a polymerase chain reaction (see Fig. 3). The specificity of this step is ensured by the use of specific primers. Primers are short stretches of DNA that initiate replication by binding to a complementary sequence in the template. Molecular tests for SARS-CoV-2 use primers for sequences from two genes Fig. 1. A simplified view of COVID-19 infection. On entry into a host cell, SARS-CoV-2 — the gene for the E protein, and the replicates and multiplies. The number of viruses in the body increase with time, and peaks at RdRp gene that makes RNA dependant around the time an infected person starts showing symptoms of disease. Our immune system RNA polymerase enzyme. Sequencing of responds to the virus by making two kinds of antibodies — called IgM (Immunoglobulin M) the SARS-CoV-2 genome shows that both antibodies & IgG (Immunoglobulin G) antibodies. Both begin to appear at about the same time genes are unique to the virus and slow to as the first symptoms of disease. IgM antibodies, which lock on to the virus particles and mutate. Primers for gene sequences from prevent them from entering cells, peak a week later. IgG antibodies, which retain ‘memory’ of related virus families are used as controls. the virus and protect us against reinfection, peak about two weeks after symptoms appear. If the virus is present in the swab, these Credits: Siouxsie Wiles & Toby Morris. URL: https://en.wikipedia.org/wiki/File:Covid-19-Time-Course-05.gif. primers will be able to initiate the License: CC-BY-SA. replication of both gene sequences. Only samples that test positive for both genes are considered to be true positives for Molecular tests are of two kinds: are labelled with fluorescent tags to COVID-19. Samples that test negative for (a) Real-time RT-PCR: This is the most act as probes. As the probes become the gene for E protein are considered to common molecular test. ‘Real-time’ part of new copies of the virus-specific be true negatives for the infection. Each refers to the fact that the concentration DNA, their tags are released into the of the 35-40 PCR cycles will double the of a certain molecule (like virus-specific solution. The fluorescence of the solution number of these sequences, amplifying DNA) is detected (using fluorescent is measured at the end of each cycle. their concentration manyfold. This allows probes) as the test (like the RT-PCR) When it reaches a level that is known easy detection of even trace amounts of is being run. To do this, some of the to correspond to 35 billion copies of the virus in a swab sample. building blocks added to build new DNA, the test is considered positive for strands in the DNA amplification step infection. The number of cycles (Ct)

Fig. 2. Different samples are collected for different tests.

(a) A nose or throat swab of potentially Fig. 3. The RT-PCR method. infected cells is used as a sample for (b) A blood sample is collected for antibody molecular or antigen tests. tests. Credits: Poshul, Wikimedia Commons. URL: https://commons.wikimedia.org/wiki/ Credits: ©Raimond Spekking, Wikimedia Commons. Credits: Truy n Hình Pháp Lu t, Wikimedia ề ậ File:Reverse_transcription_polymerase_ URL: https://tr.wikipedia.org/wiki/Dosya:Infektions- Commons. URL: https://commons.wikimedia.org/ chain_reaction.svg. License: CC-BY-SA. schutzzentrum_im_Rautenstrauch-Joest-Muse- wiki/File:Doctor_taking_blood_sample_for_ um,_K%C3%B6ln-6313.jpg. License: CC-BY-SA 4.0. COVID-19_rapid_testing.png. License: CC-BY-SA.

50 — Rediscovering School Science | Oct 2020 required to reach this number tells us around the clock. Delays in test results an independent sample. Since these what the original viral load was. In India, impact the trace (contacts of an infected tests can be run where the samples Ct < 35 is positive, Ct > 35 is negative, person), test (each contact), quarantine are collected, the results are available and Ct = 35 suggests that the test needs (those who test positive) protocol that sooner. This allows higher testing rates, to be repeated. This test is highly specific, many countries have adopted to reduce and more localised responses to the giving no false positives. It is also very spread of infection. Contacts may need spread of infection. sensitive, testing positive even if a single to be quarantined before their test virus particle is present in the swab results can be obtained to confirm the Rapid Antigen Test (RAT) sample. But it is time consuming (results necessity of this measure. Designed to detect the presence of virus take a day) and expensive. The sample proteins (antigens) that are capable of has to be collected and handled carefully (b) TrueNat tests: This test uses chip- producing an immune response in our by specially trained health professionals based, indigenously developed, battery body, this test is based on a method to minimise risk of contamination. It operated, portable RT-PCR machines called Lateral Flow Immunoassay or has to be transported to a laboratory that were originally designed for contact LFIA (see Box 2). which has uninterrupted power supply testing for TB and HIV. The swab is and air-conditioning for maintenance of treated with a lysis buffer (lysis = break This test is relatively inexpensive and the real-time RT-PCR machine. Sample up) to inactivate the virus and added quick (results are available in about 30 preparation takes about 2-4 hours, and to micro-PCR chips that are preloaded minutes), making it particularly suitable the PCR cycles take about 4-8 hours to with the necessary reagents. Each for contact tracing. On the other hand, run. Most accredited laboratories can run machine can have 1, 2 or 4 channels, antibodies against the S protein of about 200-300 tests per day, working and each channel can be used to test SARS-CoV-2 can bind to proteins of

Box 2. How does RAT work? An LFIA is designed to be used in a the accumulation of dye molecules in this the virus when colour appears in both the dipstick format or in a housed cassette part of the strip causes the test band to test and control bands. It is considered (see Fig. 4). Both involve a test strip that colour up. Similarly, when the capture negative for the virus when colour appears has a sample pad, a conjugate pad, and a antibodies in the control band bind to the only in the control band. If no colour is nitrocellulose membrane. In a RAT test, the control protein, the control band colours produced in either band, then the test is conjugate pad has a mixture of two sets up. A sample is considered positive for considered invalid. of antibodies (called primary antibodies) — one set can bind to the antigen of interest (the S protein of the SARS-CoV-2 virus) while the other can bind to a control protein that is universally found in human blood samples. Both sets of primary antibodies are conjugated to dyes. The nitrocellulose membrane has two bands of immobilised (or capture) antibodies. One of them, called the test band, has capture antibodies against a different part of the antigen of interest. Similarly, the other band, called a control band, has capture antibodies against a different part of the control protein. The antigens in a swab or sputum (coughed up) sample flow laterally across the strip through capillary action. When they reach the conjugate pad, one set of primary antibodies bind to the control protein. If the swab contains infected cells, the other set of primary antibodies bind to Fig. 4. The design of a lateral flow immunoassay. the S protein. When the capture antibodies Credits: U.S. National Aeronautics and Space Administration, Wikimedia Commons. in the test band grab onto the S protein, URL: https://commons.wikimedia.org/wiki/File:Lateral_Flow_Assay.jpg#filehistory. License: CC-BY.

— Rediscovering School Science | Oct 2020 51 other coronaviruses, increasing the likelihood of false negatives. Also, Box 3. How does an ELISA work? since it does not involve any kind of In an ELISA, part of the antigen of interest is synthesised and adsorbed onto a base, like amplification, the antigen needs to a plastic strip or a plate with wells (see Fig. 5). In the most common form of the test, the be present in sufficient quantities blood sample to be tested is diluted with a buffer and added to the plate. The plate is in a swab for it to be detected. As a incubated to allow time for virus-specific antibodies to attach to the antigen in the plate. It is then washed to remove all unbound antibodies. result, the specificity of this test can vary from 80-90%, and sensitivity can A second set of antibodies, called capture antibodies, is added to the strip or plate. Each range from 34-90%. This means that a capture antibody is linked to an enzyme molecule. Since this second set of antibodies molecular test is needed to confirm a is capable of binding to virus-specific antibodies, it will link to any antibody-antigen negative RAT result. But a positive RAT complex on the plate. After washing to remove any unbound material, the substrate for the enzyme is added to the plate. The presence of the enzyme linked to the second set result is considered a true positive for of antibodies will result in the formation of a coloured product. The intensity of colour the virus. Such patients (about 50% produced is a measure of the antibody concentration in the blood sample. of those found infected according to some reports) can get into isolation faster, reducing the chances of spread of the disease.

Antibody Tests Doctors and scientists studying a pandemic explore several questions — how many people are infected by the virus at any given point of time? How many remain asymptomatic? How many develop symptoms early, and how Fig. 5. The design of a ‘sandwich’ ELISA. many have delayed onset of symptoms? Credits: Jeffrey M. Vinocur, Wikimedia Commons. URL: https://commons.wikimedia.org/wiki/ Can someone who has recovered File:ELISA-sandwich.svg. License: CC-BY. from a COVID-19 infection catch the infection again? In addition, scientists use contact tracing to find out how test is based on the Enzyme Linked determine the exposure and spread of the virus spreads. This knowledge Immunosorbent Assay or ELISA the disease worldwide. allows health care teams to advise technique (see Box 3). This test can governments on controlling spread detect the presence of virus-specific Parting thoughts of the disease, and advise people on antibodies with a high degree of Molecular and antigen tests can help measures to remain safe. Molecular and accuracy. But because it requires a lab antigen tests can only indicate current control the pandemic by detecting the setting, it is relatively time-intensive virus in early stages of infection, even infections. Antigen tests generally pick and expensive. up signs of infection in only those who before its symptoms become evident. z A rapid serology antibody test, have severe symptoms. But we know Antibody tests help determine what like a RAT, is based on the lateral that many of those who are infected proportion of a population has been flow immunoassay technique. It is may be asymptomatic or have such exposed to the virus, and how long quick (test results are available in 15 mild symptoms that they never get their protection against reinfection minutes), relatively inexpensive, and tested. Antibody tests help us develop lasts. The more accurate these tests, can be conducted at point-of-care. a better understanding of these aspects the more effective they will be in of the pandemic. Since it can be used to screen a large combating the pandemic. Many testing number of samples at the same time, kits are available, and newer ones Antibody tests are designed to detect it is particularly useful in detecting are constantly being developed. But the presence of the IgM and IgG the spread of the disease in a large physical distancing, the use of masks, antibodies in blood serum or plasma population within a short span of time. and frequent hand washing remain the samples. They are of two kinds: Hence, the World Health Organisation most effective ways to minimise the z The most common antibody (WHO) is facilitating this test to spread of infection.

52 — Rediscovering School Science | Oct 2020 Key takeaways

• COVID-19 is diagnosed by testing for the presence of the virus or the body’s response to infection. • The usefulness of a test is measured by its specificity and sensitivity. No test is perfect. • Molecular tests (real-time and TrueNat) detect genes specific to SARS-CoV-2 in nose or throat swabs using a method called Reverse Transcription Polymerase Chain Reaction (RT-PCR). These are the most accurate tests available. • The Rapid Antigen Test (RAT) detects SARS-CoV-2 specific antigens in nose or throat swabs using a method called Lateral Flow Immunoassay. It allows quick screening of contacts of an infected person in the trace-test-quarantine protocol. • Antibody tests detect IgM and IgG antibodies in blood serum or plasma samples using an Enzyme Linked Immunosorbent Assay (ELISA) or a Lateral Flow Immunoassay. These tests are particularly useful in population-wide screening, and identification of past infections.

Note: Source of the image used in the background of the article title: https://www.flickr.com/photos/iaea_imagebank/49869473991. Credits: Dean Calma, IAEA Imagebank. License: CC-BY.

Yasmin Jayathirtha is a chemist and a chemistry teacher, with a fascination for ‘how do we find out?’ She can be contacted at [email protected].

— Rediscovering School Science | Oct 2020 53 SNIPPETS

CAN CLAPPING HANDS KILL SARS-CoV-2?

The only soundwaves known to damage bacteria and Based on current evidence, it is clear that the claim that viruses are ultrasonic waves, which are above 20 kHz. These clapping hands in unison will kill viruses and cleanse the high energy waves can disrupt biological material only air is false. when in direct contact (at distances of a few millimetres in a liquid medium), and where energy loss is minimal. Studies have shown that all forms of hand-claps generate shock waves of frequencies ranging from 1-10 kHz. Clapping with cupped hands increases enclosed volume, which causes an additional Helmholtz-type resonance. However, there is no scientific evidence to suggest that audible sound waves (vibrations that can be heard by the human ear) can destroy a virus or bacteria. Clapping creates audible frequencies (1-10 kHz) that are too low to cause any damage. No amount of resonance will cause clapping hands, even in unison, to achieve additive frequencies comparable to ultrasonic waves in the surrounding air. In addition, sound energy typically dissipates as it travels, and Source URL: https://www.pxfuel.com/en/free-photo-qsqfv. License: Public Domain becomes weaker at larger distances.

Notes: 1. This response was first published on the Indian Scientists’ Response to CoViD-19 (ISRC) website. 2. Source of the image used in the background of the article title: https://pixabay.com/illustrations/audio-sound-waves-sound-frequency-3540254/. Credits: mtmmonline, Pixabay. License: CC-0.

54 — Rediscovering School Science | Oct 2020 SNIPPETS CAN AIR-PURIFIERS PROTECT YOU FROM SARS-CoV-2?

We know that droplets and aerosols with SARS-CoV-2 virus particles are released from the nose or mouth of an infected person not only when they cough or sneeze, but also when Box 1. Did you know? they speak or breathe out. In fact, the rate of aerosol Notably, air sampled from hospital rooms of COVID-19 generation is directly proportional to speech volume. patients did not have detectable RNA from viruses, although various surfaces in the rooms as well as air Large droplets, thought to be major carriers of viral particles, vents did test positive for viral RNA. This suggests that tend to immediately fall downwards, and settle onto the potential for transmission through surfaces could surfaces within a radius of 2 m (or 6 feet). Most common be greater than through contaminated air. However, domestic air filters circulate only small volumes of air at a rooms sampled in the study routinely underwent time, taking a while to sample the entire air in the room. a complete air exchange; and the study sampled a Therefore, most infectious droplets would likely settle down relatively small volume of air. Hence, further tests are before reaching the filter, rendering the filter ineffective. needed to confirm whether infection is more likely to be transmitted via contaminated surfaces or via air Being smaller in size, aerosols do not settle down easily, flow in a closed room. and can be carried to the filter in an air purifier. Aerosols with infective particles are more likely to be generated during certain medical procedures in a hospital, where air purification may be more critical (seeBox 1). However, Not all air purifiers sold in the market have HEPA filters. the role of aerosols in transmission of the SARS-CoV-2 However, the efficacy of even HEPA-fitted air-purifiers in infection (‘airborne’ transmission) is not clear yet. reducing the risk of SARS-CoV-2 infection is questionable, According to the World Health Organization (WHO) and since these purifiers take time to filter all the air in a Centers for Disease Control and Prevention (CDC), this virus closed room. If an air purifier with HEPA filters is used spreads primarily through proximity and contact. in a COVID-19 patient’s room, the filter must be cleaned frequently, and proper protection and sanitation measures Manufacturers of domestic air purifiers claim that SARS- must be used while cleaning. CoV-2 exhaled by infected persons can be removed by their product. However, only HEPA (High Efficiency Particulate In a domestic setting, the concentration of shed viral Air) filters can do this. According to a NASA study (2016), particles can be reduced by maintaining good circulation these filters can remove over 99.9% of particles smaller of fresh air. This can be achieved, for example, by opening than a micron (1000 nanometers). Since the diameter of the windows, and regularly disinfecting surfaces. Currently, SARS-CoV-2 is about 0.125 microns (125 nanometers), it there is no evidence showing that HEPA certified air can be captured by a HEPA filter. purifiers are more effective than this simple strategy.

Notes: 1. This response was first published on the Indian Scientists’ Response to CoViD-19 (ISRC) website. 2. Source of the image used in the background of the article title: https://commons.wikimedia.org/wiki/File:HEPA_Filter.png. Credits: BruceBlaus, Wikimedia Commons. License: CC-BY-SA.

— Rediscovering School Science | Oct 2020 55 OUR RESPONSE

TREATMENTFOR A PANDEMIC: AN ONGOING SEARCH SRIKANTH. K. S

he ongoing COVID-19 pandemic, Based on how host-virus interactions Is there a cure for caused by the SARS-CoV-2 virus, correlate with clinical symptoms, COVID-19? Does everyone Thas affected millions around three phases of COVID-19 disease with the disease require the globe, and caused thousands of progression have been proposed treatment? At what deaths. Until large-scale vaccination — an incubation or early infection becomes a possibility, the outbreak is phase, a pulmonary phase, and a stage of infection does being managed through public health treatment become hyperinflammatory phase (seeFig. 1). measures to slow the spread of infection While these phases can show much essential? What are the and supportive measures to treat the overlap, their identification can help different approaches infected. How do we treat a disease in more effective treatment. For caused by a ‘novel’ pathogen? that are used to treat example, containment of the virus COVID-19 patients? would be more important in the first What are some of the key Approaches to treatment phase, whereas immunosuppressive concerns, side-effects, Not everyone infected with COVID-19 treatment would be more helpful in and limitations of each requires treatment. The immune the second and third phases. approach? response that SARS-CoV-2 virus triggers in our body is, in most cases (~ 81% of As of now, no specific drug is known people), enough to resolve the infection to prevent or treat this infection. with no (asymptomatic), or a few mild But researchers across the world symptoms. More severe or critical are working on two strategies — symptoms are seen only when damage designing new drugs, and repurposing caused by the virus is combined with existing drugs (see Box 1). Based on a dysfunctional (out of proportion) how they act, these pharmacological immune response. approaches are of two kinds:

56 — Rediscovering School Science | Oct 2020 z Those that target the novel virus: cardiovascular conditions, or diabetes) development within the host, giving the This includes drugs that prevent viral tend to be at greater risk of developing host’s immune system time to mount invasion, and protect host cells from severe illness. Also, severe cases of a response against the virus. Most infection. For example, inhibitors of COVID-19 show a strong inflammatory antiviral drugs are directed against cellular enzymes (like proteases and response (hyperinflammatory phase) virus-specific replication processes. furins) help prevent the assembly of with an overwhelming release of Since virus replication occurs within new viruses, while endosomal entry cytokines (called a cytokine storm). host cells and uses the host cellular inhibitors may prevent the entry of the This plays a critical role in respiratory machinery, the challenge is to develop virus into host cells. Drugs affecting failure. Drugs that target this irregular drugs that inhibit the virus without viral replication can prevent the spread inflammatory response can help manage harming the host. Hence, drugs against of infection within our body. such symptoms. other coronaviruses like SARS-CoV z Those that can help treat symptoms and MERS-CoV, or viruses like HIV, are of the disease: This includes drugs that Antiviral drugs being explored for COVID-19 treatment. can reduce disease severity and risk of Unlike antibiotics (which act against Repurposing antivirals is not simple — a death. For example, people with ongoing bacteria), antiviral drugs do not drug that works against SARS-CoV or inflammation (due to hypertension, ‘kill’ the virus. They only inhibit its MERS-CoV may not necessarily work against SARS-CoV-2. Despite these limitations, antivirals like remdesivir, lopinavir-ritonavir, favipiravir, tenofovir, and ribavirin have shown some promising results against SARS-CoV-2 (see Box 2). Clinical trials will help determine their safety and efficacy in COVID-19 treatment.

Convalescent Plasma Therapy (CPT) This approach, also known as Therapeutic Plasma Exchange (TPE), was found to be useful during the SARS pandemic. It is based on

Box 1. New and old drugs: The design of new drugs is affected by limitations in our understanding of SARS-CoV-2 biology, and the host-pathogen interactions that lead to COVID-19. Also, the process of drug development, like that of new vaccines, is expensive, time- consuming, and has a very low success rate. Some reports suggest that only 1 out of 10,000 preclinical 1 Fig. 1. COVID-19 progression with common symptoms and likely treatment strategies. Each compounds reaches the market. In phase is characterized by a different type of biological interaction between SARS-CoV-2 and contrast, repurposing existing drugs the body’s immune response. In Phase I, or the early infection or incubation phase, the (developed against similar viruses, or SARS-CoV-2 virus infects cells in the respiratory tract, replicates within them, and releases with the ability to treat the same/ new viral particles. In Phase II, or the pulmonary phase, the infection reaches the lungs and related symptoms) requires tests the body’s immune system is strongly affected by it. In Phase III, or the hyperinflammatory for safety and efficacy in treating phase, the virus moves from the lungs to the blood, reaching and infecting other body organs. different disease phases. Since this is The body’s response against the virus is amplified to an extent where it may cause injury to its relatively faster, many existing drugs own organs. All three phases are seen only in severe cases. and treatment regimens are currently Credits: Adapted from an image by Romagnoli S., Peris A., De Gaudio A.R & Geppetti P. in ‘SARS-CoV-2 undergoing clinical trials. and COVID-19: From the Bench to the Bedside’. Physiological Reviews. URL: https://doi.org/10.1152/ physrev.00020.2020.

— Rediscovering School Science | Oct 2020 57 Box 2. Repurposing antivirals: Remdesivir, a drug against Ebola (also an multiple-organ-dysfunction syndrome, the lopinavir-ritonavir combination include RNA virus), affects RNA dependent RNA septic shock, and acute kidney injury.3 severe skin eruptions, anaemia, lower blood polymerase — an enzyme that is essential The Drug Controller General of India WBC count, inflammation of the pancreas, for RNA virus replication and protein (DCGI) has approved the use of remdesivir and liver injury.4 The Indian Council of synthesis.2 It is active against SARS-CoV-2, for emergency use to treat hospitalised Medical Research (ICMR) advises restricted SARS-CoV, and MERS-CoV in laboratory patients with severe COVID-19. public health emergency use of lopinavir- (in vitro) tests and in animal (in vivo) Lopinavir-ritonavir combinations have ritonavir combination therapy for severe studies. But its adverse effects include skin been used during SARS and MERS outbreaks. COVID-19 patients. rashes, loose stools, rise in liver enzymes Lopinavir, an anti-HIV drug, inhibits the Favipiravir, an anti-influenza drug, is (indicating liver damage) and creatinine folding of viral proteins by inhibiting the undergoing clinical trials for treatment (indicating poor kidney function), and virus-specific enzyme aspartate protease. against SARS-CoV-2, especially in low blood pressure. In some cases, it Ritonavir acts by increasing the serum combination with drugs like chloroquine can lead to more serious conditions, like concentration of lopinavir. Adverse effects of phosphate and tocilizumab.

the principle that a person who Drugs against other act on a cell if it can bind to specific has recovered from a COVID-19 membrane receptors, and drugs like infection would have neutralizing pathogens tocilizumab, itolizumab, sarilumab, and immunoglobulins (antibodies) against Drugs against other pathogens can siltuximab can inhibit these receptors. SARS-CoV-2 in their blood plasma act in ways that could help treat Thus, the DCGI has approved the use (convalescent plasma). When this viral infections. For example, the of tocilizumab, and a similar drug antimalarial drugs chloroquine and plasma (the liquid part of blood minus itolizumab, for emergency use in hydroxychloroquine, the antiparasitic the blood cells) is transferred to an severe COVID-19 patients. Tocilizumab drug ivermectin, and the antibiotic infected person, the anti-SARS-CoV-2 is a humanized monoclonal antibody azithromycin are now being studied for antibodies would neutralize the virus (monoclonal antibodies are produced anti-SARS-CoV-2 activity (see Box 3). in the recipient (see Fig. 2). by a single cell and bind to the same region of an antigen) that blocks the The challenge for this therapy lies in Monoclonal antibodies/ IL-6 receptor. Originally developed for finding healthy donors with high titres IL-6 pathway inhibitors rheumatoid arthritis, it is recommended of neutralizing antibodies. The plasma for use in CRS.15 Results of clinical trials donors need to have had COVID-19, In critically ill patients, mild or severe to evaluate the safety and efficacy of but been completely symptom-free for cytokine release syndrome (CRS) could lead to Acute Respiratory Distress tocilizumab and sarilumab in severe at least 14-28 days before donation. Syndrome (ARDS). A cytokine can only They need to test negative for COVID-19 pneumonia are awaited. COVID-19, and have high SARS-CoV-2 neutralizing antibody titres. They also need to be healthy enough to donate plasma. The potential risks of convalescent plasma therapy include transfusion-related allergic reactions and pathogen transmission.5 Preliminary studies have shown a decrease in nasopharyngeal SARS- CoV-2 viral load, reduction in COVID-19 disease severity, and improved blood oxygenation after 12 days of CPT.6 However, these studies are limited by small sample sizes and lack of robust data. In India, the ICMR has approved Fig. 2. How does Convalescent Plasma Therapy work? a multicentric phase-II clinical trial to Credits: Adapted from an image by David H. Spach, University of Washington – Infectious Diseases test the efficacy of CPT on COVID-19 Education & Assessment (IDEA) platform. URL: https://covid.idea.medicine.uw.edu/page/treatment/drugs/ patients with moderate illness. human-coronavirus-immune-plasma-hcip#figures.

58 — Rediscovering School Science | Oct 2020 Box 3. Repurposing drugs against other pathogens: Chloroquine (CQ) and its analogue lack of placebo control (that eliminates the SARS-CoV-2 replication.10 It has been Hydroxychloroquine (HCQ) inhibit possibility of therapy due to psychological suggested that combination therapy SARS-CoV-2 in vitro. HCQ is possibly the processes rather than physiological ones). of ivermectin with other drugs may be more potent of the two.7 Their antiviral Recent studies suggest that HCQ has no beneficial. mode of action is not clear, but could beneficial effects in patients hospitalized Azithromycin has been shown to have involve inhibition of pH-dependent with COVID-19. A few preliminary studies anti-inflammatory activity in vitro and in steps of viral replication. They are also even suggest that treatment with CQ/HCQ clinical studies11, as well as antiviral activity believed to act as immunomodulators, may be associated with similar or even against Zika and Ebola viruses in vitro.12 inhibiting tumour necrosis factor-alpha increased risk of death, especially when It induces the same cytokines (like IFN- , 9 (TNF- ) and interleukin-6 (IL-6) — used in combination with azithromycin. IFN- and IFN- ) that the body produces cytokines that in excessive amounts lead In India, the ICMR has advocated the in response to viral infection and are α to hyperinflammation.α 8 Initial studies on supervised prophylactic use of CQ/HCQ knownβ to inhibitλ viral replication in host COVID-19 patients claimed that HCQ use in high-risk populations like health care cells.13 Preliminary studies in COVID-19 was associated with faster recovery time, workers, and therapeutic use in severely ill patients have shown that azithromycin decreased nasopharyngeal shedding of the COVID-19 patients. can influence the course of viral infection virus, improved lung health, and a lower Ivermectin, used against HIV and and clinical outcomes for the better.14 chance of progression to severe illness. dengue viruses, acts by inhibiting the But further studies and validation will These studies have been questioned due replication and assembly of new virions. be needed before its use in COVID-19 to their small sample sizes, lack of double In vitro studies have shown that high treatment can be recommended, especially blinding (that minimises risk of bias), and concentrations of this drug can inhibit in combination with HCQ.

Systemic corticosteroids used in many autoimmune, infectious, Anticoagulants and neuromuscular disorders for its Corticosteroids are steroid hormones COVID-19 patients have been reported immunomodulatory effects.17 Since that regulate inflammation and the to have a higher incidence of venous it was reported to have benefits with immune response. Though systemic thromboembolism. In this condition, tolerable side-effects in SARS and MERS corticosteroids are not recommended blood clots from leg and arm veins travel patients, IVIg therapy is now being used for the treatment of viral pneumonia to the lungs and cause blockage. The on a case-by-case basis for COVID-19 or ARDS, glucocorticoids such as use of anticoagulants (commonly called patients. Trials are underway to evaluate methylprednisolone may be of limited blood thinners) has been associated the efficacy of high-dose IVIg in severe help in severe COVID-19 induced with reduced ICU mortality. Hence, the COVID-19 patients. ARDS. A recent study showed that use of anticoagulants like enoxaparin dexamethasone, another glucocorticoid, or heparin to prevent clot formation in reduced fever and mortality among Cell and biological COVID-19 is being explored.19 The World critically ill COVID-19 patients.16 therapy Health Organization (WHO) recommends However, evidence from the use of Mesenchymal Stem Cells (MSCs) are stem the use of prophylactic heparin against systemic corticosteroids in treatment of cells from our bone marrow that form venous thromboembolism in severe to SARS and MERS indicates a likelihood of and repair skeletal tissues like bones critically ill COVID-19 patients, unless harmful side effects to the body without and cartilages. They have been shown they are suffering from active bleeding clear benefit in treating symptoms to have strong immunomodulatory or low platelet count etc. of infection. The Ministry of Health effects. Hence, MSCs have been used for and Family Welfare, Govt. of India, treatment of immune-mediated disorders Parting thoughts advises the use of dexamethasone as like systemic lupus erythematosus (where Finding a cure for COVID-19 is a matter an alternative to methylprednisolone in the immune system attacks healthy of great urgency. But it is important moderate to severe COVID-19 cases. tissue) and graft-versus-host disease to note that many pharmacological (where the recipient of a transplant is therapies that have shown potential High-dose intravenous attacked by cells of the graft).18 Today, need to be studied extensively, especially immunoglobulin (IVIg) scientists are exploring the possibility for adverse effects and their long- of using MSCs to reduce the cytokine IVIg are polyclonal immunoglobulins term consequences. Clinical trials are storm caused by a dysfunctional immune or antibodies that are produced by underway in multiple countries to response to the SARS-CoV-2 virus. One different B cells and can bind to address some of these issues. The need concern regarding this line of treatment different parts of the same antigen. of the hour is to coordinate research is the possibility of causing adverse long- Extracted from healthy donors, IVIg is efforts across the globe for effective term effects on the immune system. anti-SARS-CoV-2 drug design.

— Rediscovering School Science | Oct 2020 59 Key takeaways

• The immune response that SARS-CoV-2 triggers in our body is enough to resolve disease in most cases. Treatment is necessary only for those with severe or critical symptoms. • Identifying the phase of disease progression — early infection, pulmonary or hyperinflammatory — can help in more effective treatment. • Two strategies — designing new drugs, and repurposing existing drugs — are being explored to find drugs that can help prevent or treat COVID-19. • Depending on their mode of action, pharmacological approaches to COVID-19 treatment either target the novel virus, or help treat symptoms of the disease. • Treatment strategies involving the use of antiviral drugs, Convalescent Plasma Therapy, and repurposed drugs against other pathogens are being explored for their ability to target the novel virus. • Treatment strategies involving the use of monoclonal antibodies/IL-6 pathway inhibitors, corticosteroids, high-dose intravenous immunoglobulins (IVIg), cell and biological therapy, and anticoagulants are being explored for their ability to treat symptoms of COVID-19. • Many promising pharmacological therapies need to be studied extensively, especially to understand their adverse effects and long-term consequences.

Note: Source of the image used in the background of the article title: https://pixnio.com/media/covid-19-gloves-latex-sars-cov-2-syringe. Credits: Bicanski. License: CC-0.

References: 1. Moreno L., Pearson A.D. How can attrition rates be reduced in cancer drug import able to inhibit replication of HIV-1 and dengue virus. Biochem. J. discovery? Expert Opinion on Drug Discovery. 2013; 8:363–368. 2012;443(3):851–856. 2. Mulangu S, Dodd LE, Davey RT Jr, Tshiani Mbaya O, Proschan M, Mukadi D, 11. Jaffé A., Bush A. Anti‐inflammatory effects of macrolides in lung disease. et al. A randomized, controlled trial of Ebola virus disease therapeutics. N Pediatr. Pulmonol. 2001; 31:464–473. Engl J Med. 2019;381(24):2293–303. 12. Retallack H., Di Lullo E., Arias C., Knopp K.A., Laurie M.T., Sandoval- 3. Grein J, Ohmagari N, Shin D, Diaz G, Asperges E, Castagna A, et al. Espinosa C., Mancia Leon W.R., Krencik R., Ullian E.M., Spatazza J., Pollen Compassionate use of remdesivir for patients with severe Covid-19. N A.A., Mandel-Brehm C., Nowakowski T.J., Kriegstein A.R., DeRisi J.L. Zika Engl J Med 2020. doi: 10.1056/NEJMoa2007016. virus cell tropism in the developing human brain and inhibition by 4. Kaplan SS, Hicks CB. Safety and antiviral activity of lopinavir/ritonavir- azithromycin. Proc. Natl. Acad. Sci. U. S. A. 2016;113(50):14408–14413. based therapy in human immunodeficiency virus type 1 (HIV-1) infection. 13. Menzel M., Akbarshahi H., Bjermer L., Uller L. Azithromycin induces anti- J Antimicrob Chemother. 2005;56(2):273–6. viral effects in cultured bronchial epithelial cells from COPD patients. Sci. 5. COVID-19 Treatment Guidance Writing Group. JHMI clinical guidance Rep. 2016; 6:28698–28709. for available pharmacologic therapies 2020 [updated 25 March 2020]. 14. Damle B., Vourvahis M., Wang E., Leaney J., Corrigan B. Clinical Available from: https://www.hopkinsguides.com/hopkins/view/Johns_ pharmacology perspectives on the antiviral activity of azithromycin and Hopkins_ABX_Guide/540747/all/Coronavirus_COVID_19__SARS_CoV_2_. use in COVID‐19. Clin. Pharm. Therap. 2020. 6. Shen C, Wang Z, Zhao F, Yang Y, Li J, Yuan J, et al. Treatment of 5 critically 15. Mehta P, McAuley DF, Brown M, Sanchez E, Tattersall RS, Manson JJ, et al. ill patients with COVID-19 with convalescent plasma. JAMA 2020. doi: COVID-19: consider cytokine storm syndromes and immunosuppression. 10.1001/jama. 2020.4783. Lancet. 2020;395(10229):1033–4. 7. Yao X, Ye F, Zhang M, Cui C, Huang B, Niu P, et al. In vitro antiviral activity 16. Cinzia Solinas, Laura Perra, Marco Aiello, Edoardo Migliori, Nicola and projection of optimized dosing Design of Hydroxychloroquine for the Petrosillo. A critical evaluation of glucocorticoids in the management of treatment of severe acute respiratory syndrome coronavirus 2 (SARS- severe COVID-19. Cytokine Growth Factor Rev. 2020 Jun 24. CoV-2). Clin Infect Dis. 2020. 17. Ferrara G, Zumla A, Maeurer M. Intravenous immunoglobulin (IVIg) for 8. Savarino A, Boelaert JR, Cassone A, Majori G, Cauda R. Effects of refractory and difficult-to-treat infections. Am J Med 2012; 125:1036. e1-8. chloroquine on viral infections: an old drug against today’s diseases? 18. Leng Z, Zhu R, Hou W, Feng Y, Yang Y, Han, et al. Transplantation of Lancet Infect Dis. 2003;3(11):722–7. ACE2(-) mesenchymal stem cells improves the outcome of patients with 9. Andrea Cortegiani, Mariachiara Ippolito, Giulia Ingoglia, Pasquale Iozzo, COVID-19 pneumonia. Aging Dis 2020; 11:216-28. Antonino Giarratano, Sharon Einav Update I. A systematic review on the 19. Kollias A, Kyriakoulis KG, Dimakakos E, Poulakou G, Stergiou GS, efficacy and safety of chloroquine/hydroxychloroquine for COVID-19. J Syrigos K. Thromboembolic risk and anticoagulant therapy in COVID-19 Crit Care. 2020 Oct; 59: 176–190. patients: emerging evidence and call for action. Br. J. Haematol. 2020 10. Wagstaff K.M., Sivakumaran H., Heaton S.M., Harrich D., Jans D.A. Jun;189(5):846-847. Ivermectin is a specific inhibitor of importin α/β-mediated nuclear

Srikanth. K. S is an independent research consultant. He has a doctorate in immunology, and his primary area of interest is host-pathogen interactions. He can be contacted at [email protected].

60 — Rediscovering School Science | Oct 2020 SNIPPETS

MENTAL HEALTH OF CHILDREN DURING THE COVID-19 OUTBREAK

How can the COVID-19 outbreak z Talk about the outbreak keeping in mind your child’s developmental level, and by following their cues. affect the mental health of young Encourage the child to ask questions, and answer in children? ways that balance honesty (for example, we need to Children respond to stressors in different ways depending stay indoors to make sure we are safe) with comfort upon their age, previous experiences, and the coping (for example, we are doing what we can to stay safe mechanisms that they typically use to manage stress. In the such as washing our hands; the virus is rare among present situation, the emotional health of children might children). be impacted by: z It is natural for parents to have fears and concerns z Their awareness of stress experienced by those close to at this time, and children tend to pick up on their them. parents’ feelings (see Box 1). Thus, engaging in self- z Disruption of their regular structure and routine care and managing one’s own mental health concerns (school, playdates, physical connections, etc.). will help parents provide a calm and reassuring space for their children. z The way information is presented to children. This can play a significant role in impacting their mental health. Giving incomplete or age-inappropriate information How can I talk to my child about the can contribute to greater levels of stress in children. COVID-19 outbreak? Since younger children thrive on routine, they can z Offer reassurance and comfort while talking about the experience distress because of a lack of structure. Older outbreak. children might be especially attuned to the ways in z Listen to information that the child already knows, and which physical distancing is changing their typical social add to it as needed. connections with others outside of their homes. Special z Make sure to check in about possible concerns and worry attention needs to be directed towards children with experienced by the child, and offer a space to talk. special needs, past mental health concerns, and those living in abusive environments. This population is more vulnerable to developing mental health concerns without Box 1. Mental health of parents: support and resources. Parents might already be experiencing stress regarding various aspects of the outbreak, such as How can I help my child cope with the concerns about the economy, jobs, contracting illness, present situation? and an uncertain future. In addition, parents are z Since children need structure, try and work on a likely to face the responsibility of helping members of schedule for the day that would create a flexible their family (especially children) to maintain a regular routine for the family and the child. It is important to routine and stay connected with friends and family. keep in mind that this routine needs to work best for In many ways, parents might be expected to continue your family. with their typical responsibilities at work and at home, without being able to access the support that z Think of innovative activities and physical exercises was available to them before the outbreak. These that the child can engage in at home. circumstances might contribute to greater levels of z Offer support, reassurance, and care by listening to, and stress within the family. recognizing the emotions expressed by young children.

— Rediscovering School Science | Oct 2020 61 z It can help to focus the conversation towards solution period of time (2-4 weeks). Another indicator of needing finding and building safety. This helps the child feel professional support could be when the child’s behaviour empowered. disrupts typical life within the family unit.

z Share facts while tending to things that are within control (for example, washing hands to stay safe, physical Where can I find additional information? distancing will keep us safe). z Centers for Disease Control & Prevention’s ‘Helping

z Be attuned to your own mental health concerns and stress Children Cope with Emergencies’. URL: https://www.cdc. levels as parents, and recognise when you might need some gov/childrenindisasters/helping-children-cope.html. time for self-care in order to engage in these conversations. z Centers for Disease Control & Prevention’s ‘Talking with children about Coronavirus Disease 2019’. URL: https:// www.cdc.gov/coronavirus/2019-ncov/daily-life-coping/ talking-with-children.html?

z World Health Organisation’s ‘Helping children cope with stress during the COVID-19 outbreak’. URL: https:// www.who.int/docs/default-source/coronaviruse/helping- children-cope-with-stress-print.pdf.

z We are Teachers’ ‘Things to do during COVID-19’. URL: https://www.weareteachers.com/things-to-do-during- covid/.

z Inter-Agency Standing Committee Reference Group on Mental Health and Psychosocial Support in When do I reach out for professional Emergency Settings or IASC MHPSS RG’s ‘My Hero is help to support my child? You, Storybook for Children on COVID-19’. URL: https:// Keep in mind that parents know their child best, and each interagencystandingcommittee.org/iasc-reference-group- child responds differently to stress. Parents who have tried mental-health-and-psychosocial-support-emergency- strategies to ease and soothe their child over a period of settings/my-hero-you. time without success might feel stuck and overwhelmed. z United Nations Children's Fund's (UNICEF) ‘How to Professional help should be sought out if parents have tried protect your family’s mental health in the face of different strategies with no reduction in the frequency COVID-19’. URL: https://www.unicef.org/coronavirus/how- (number of times behaviour is observed) and intensity protect-your-familys-mental-health-face-coronavirus- (power of the behaviour) of said behaviour over a substantial disease-covid-19.

Notes: 1. These responses were first published on the Indian Scientists’ Response to CoViD-19 (ISRC) website. 2. Source of the image used in the background of the article title: https://pixabay.com/photos/tree-watering-child-planting-3335402/. Credits: 9lnw, Pixabay. License: CC-0.

62 — Rediscovering School Science | Oct 2020 SNIPPETS

Credits: CovidGyan. URL: https://covid-gyan.in/content/covid19-vaccine-mrna-vaccine. License: CC-BY-NC-SA 4.0.

— Rediscovering School Science | Oct 2020 63 Oct 2020 |

— Rediscovering School Science — Rediscovering Credits: CovidGyan. URL: https://covid-gyan.in/content/coronavirus-stays-infectious. License: CC-BY-NC-SA 4.0. License: CC-BY-NC-SA CovidGyan. URL: https://covid-gyan.in/content/coronavirus-stays-infectious. Credits:

SNIPPETS 64 MITIGATION OUR RESPONSE OF THE COVID-19 EPIDEMIC

T JACOB JOHN

What does ‘mitigation’ OVID-19 emerged in China only context of the person-to-person mean? At what stage towards the end of 2019. Since transmission of SARS-CoV-2. This of an epidemic does it Cits symptoms superficially means that the infection spreads resembled those of already known become essential? How when people are physically close to diseases, particularly influenza and each other during, for example, work, do we use the principles pneumonia of various causes, it was travel in public transport, or social of mitigation to combat only in December 2019 that the or religious functions. However, not a new disease? Why does disease was recognised as being new to everyone involved in social interactions physical distancing and humans. How do we control the spread with an infected person gets infected the use of masks help? of a new infectious disease? themselves. Oral or nasal droplets How do we minimise the Epidemiologists use two different and ‘fomites’ act as the vehicles of risk of infection in those approaches to engage with this transmission. The seemingly hair- most vulnerable to severe question. The first approach is to splitting distinction between the forms of the disease? reduce the incidence of the disease. context and the vehicle of transmission This requires a recognition of the is important in controlling spread causes of disease and the origins of of infection. The first strategy for the pathogen. In January 2020, a novel community-level control of spread coronavirus, called SARS-CoV-2, was is generally known as containment. identified as the cause of COVID-19. Used at the start of an outbreak, While the origins of the SARS- this strategy relies on tracking the CoV-2 virus have been assigned to a dissemination of the infection or particular species of bats in China, the disease. Physical isolation or individual circumstances of its entry in humans quarantines are used to keep remain an unsolved puzzle. The second potentially infected people and their approach is to control the extent and contacts from spreading the infection rate at which the infection spreads to others. Hand-hygiene minimises in human populations. This requires fomite transmission. Once an outbreak an understanding of the modes of has spread as rapidly as COVID-19, transmission of the pathogen. Social epidemiologists recommend the use of contact (physical proximity) is the mitigation strategies (see Box 1).

— Rediscovering School Science | Oct 2020 65 Principles and practice of mitigation Mitigation is aimed at preparing a nation’s healthcare system for the challenge of minimising the spread of infection and reducing mortality. Rapid expansion of an epidemic can overwhelm a nation’s healthcare system when the number of hospital beds (particularly intensive care beds) available may be insufficient for all those in need. The high demand for hospital beds is due to the larger proportions of severe cases, and cases with complications arising within a short time span. This is why slowing Fig. 1. Mitigation measures can help flatten the epidemic curve. down the expansion of the epidemic, Credits: Adapted from an image by RCraig09, Wikimedia Commons. URL: https://en.wikipedia.org/wiki/ File:20200403_Flatten_the_curve_animated_GIF.gif. License: CC-BY-SA. usually referred to as ‘flattening of the epidemic curve’, is a salubrious and wise course (see Fig. 1). This can silent ones) from broadcasting droplets, the safer social interactions become from be achieved through two methods. The and protects uninfected people from high risk of infection. This is one of the first is to encourage people to avoid inhaling droplets that escape from most effective ways to flatten the curve, the context of transmission. This can be infected people (see Box 2). especially in countries with population ensured if each person keeps a minimum densities that are as high as in India. physical distance of 2 m (or 6 feet) from This is especially important in other people. The second method is to interactions with older people, even While COVID-19 spreads like influenza minimise risk of contact with the vehicle within their homes. It is highly (the same vehicles of transmission are at of transmission. This can be ensured recommended that older people (as well play in both diseases), it carries a 10-30 by encouraging people to wear face as each person they interact with) wear fold higher risk of death. Hence, another important element of mitigation is masks during any social interaction that masks, and practice good hand hygiene requires physical nearness of up to 1 (washing their hands with soap and m (or 3 feet). Wearing a mask prevents water after every contact). The greater Box 2. What are silent infections? people with SARS-CoV-2 infection (even the number of people who wear masks, Like all communicable diseases, COVID-19 is characterised by a particular set of signs and symptoms. Box 1. The making of a pandemic: These appear between 2-14 days after To begin with, no human had prior of Health, Indian Council of Medical exposure to SARS-CoV-2. Also, while exposure to the virus. Hence, none of us Research), Worldometer Coronavirus, and SARS-CoV-2 infection can lead to were immune to it. Since international Wikipedia have detailed data on India’s severe and life-threatening disease in travel for business or pleasure is popular, epidemic. While April-May-June were some cases, half to two-thirds of people people acted as vectors of transmission. epidemic months in major cities, we saw infected with the virus may experience The virus spread across all national epidemics in smaller cities in May-June- no signs of illness. Such infections, boundaries. By early February this year, July, and rural epidemics in June-July- where people can transmit the virus at least seven countries were infected August. Thus, spatially and temporally, before they develop disease (pre- — it was already a pandemic. By early many asynchronous epidemics add up symptomatic) or without developing March, people living in many more to the statistical construct of the one disease (asymptomatic), are called silent infections. These can result in ‘silent countries, across all the continents, country-epidemic. This epidemic may th transmission’. Young people are more had been infected. On 11 March, 2020 peak in September, and start declining likely to have asymptomatic infections, the World Health Organisation (WHO) in October through January-February or only experience very mild symptoms declared it a pandemic. 2021. Thereafter, the infection will that are not enough to feel sick. It The progression of the epidemic in most probably remain endemic to is also important to remember that India is by now common knowledge. In human communities, with low seasons quarter to half of the people infected addition to national websites (Ministry alternating with high seasons. with the virus may test negative for it.

66 — Rediscovering School Science | Oct 2020 mortality reduction. COVID-19 mortality diseases or treatment (such as cancers population-level mortality. However, has four determinants: and cancer therapies); and the advantage of a young population is lost if its not possible to provide z The inherent virulence of the z The competence and correctness timely access to quality healthcare to coronavirus (no specific antiviral drug of diagnoses and treatment of severe individuals in dire need of it. treatment is available); symptoms (see Box 3). z The age of the infected (progressively One effective way to mitigate mortality Parting thoughts increasing for those in the age group of in those most vulnerable to it (the elderly Given the scale of the ongoing 55-60 years and above, presumably on and those with comorbidities) is to pandemic, awareness and practice account of immunological senescence); prevent it in the first place. This can be of mitigation measures become z Predisposing comorbidities (diseases done by cocooning them in their homes especially important. One of the or conditions that occur together) such using a reverse quarantine approach. primary responsibilities of governments as diabetes, chronic cardio-vascular, lung We, in India, have the advantage of a across the world is to ensure that or kidney diseases, immunosuppressive youngish demography, which can reduce every citizen has access to an accurate

Box 3. Clinical diagnosis of disease: The clinical diagnosis of any disease is not based on a single lab test. For example, general clinical diagnosis of COVID-19 is based on a set of seven ‘major’ and six ‘minor’ criteria (see Table I). These are unrelated to major and minor symptoms, and should not be confused with them. At least three major criteria are necessary to diagnose COVID-19 if they include (3) or (7). In the absence of (3) and (7), COVID-19 is diagnosed by the presence of at least three other major criteria, plus at least two minor criteria. However, these criteria may not be fulfilled in the elderly (≥ 65 years of age) and those with chronic non-communicable diseases. People in these categories may show only subtle symptoms, like low grade fever, delirium, drowsiness or postural instability. Such patients should be tested with pulse oximetry and/or chest imaging, and if the results from either fits major criterion (6) or (7), they must be immediately hospitalised for medical management. The manifestations of COVID-19 in children below 5 years of age may also be different from those described above. If found necessary, doctors may carry out an RT-PCR test on a deep nasal swab or throat swab. Remember, an RT-PCR test detects only infection, not disease. Even with infection detection, there is a need to be cautious in interpreting RT-PCR results. Deep nasal swabs from two-thirds of cases, and throat swabs from nearly half the cases will test positive in an RT-PCR test. The rest may be false negatives. This means that even when a clinical diagnosis shows the presence of disease, the patient may test negative in an RT-PCR test. While tests for rapid detection of viral antigens are now available, analysis of their performance characteristics are awaited.

Table I. Major and minor criteria for clinical diagnosis of COVID-19:

Major Criteria Minor Criteria

1. Fever ≥ 3 days a. Headache/body aches/myalgia

2. Cough b. Severe fatigue/lassitude

3. Loss of smell (with or without loss of taste) c. Diarrhoea with or without vomiting

4. Breathing rate at rest ≥ 25/minute (normal rate is 12-16 breaths/ d. Pink eye (conjunctival redness with or without secretions) minute)

5. Crepitations (crackling or rattling sound made when breathing) e. Skin lesions (that can be non-itchy, maculopapular, when the chest is auscultated (examined for internal sounds) with erythematous, urticarial, or vesicular) a stethoscope

f. Normal or low normal total count of White Blood Cells 6. Oxygen level of ≤ 94%, measured by finger pulse oximeter (WBCs) with ≤ 20% lymphocytes (one type of WBCs).

7. Patchy pneumonia, in a computerised tomography (CT) scan or X-ray. Shown as streaky shadows or ground-glass appearance in both lungs. But this is not localised to a section or a lobe as seen in lobar pneumonia, and does not involve the replacement of lung tissue with cavities as seen in cavitary lesions.

Note: This is put together by the author and is yet to be validated by research.

— Rediscovering School Science | Oct 2020 67 Box 4. Lockdowns: A lockdown is an extreme and livelihoods of people. Its Keeping shops selling essential to a rapid expansion of the form of ensuring physical worst impacts are experienced items open minimises the pandemic in their home states distancing between people by the poor, daily wage need to hoard. Similarly, some from April through June. In outside households. More than earners, small-volume traders, 30 million people who had contrast, a partial lockdown 100 countries across the world farmers, and children. In some migrated (many with families) could involve closure of schools have used complete or partial cases, it can also have the for work/employment to and non-essential assemblies lockdowns to enforce physical exact opposite effect than southern and western states for recreation, exercise, distancing between people that desired. For example, were caught unawares by partying, religious meetings, outside households. blocking all services during the lockdown. These workers eating in restaurants etc, while A complete lockdown severely the lockdown in India caused became carriers of the virus keeping essential services such affects the economy and, a huge surge in panic-buying when they trickled back to as food shops, groceries, and more importantly, the lives for stocking essential supplies. their home states. This led open-air parks etc., open.

understanding of the problem. The for effective mitigation, through an successful, efforts against the AIDS other is to educate and facilitate approach that combines access to epidemic during the 1980s and 1990s. the behavioural changes involved accurate information, communication, But this is not enough. Each individual in effective mitigation so that the and behaviour change education is has the responsibility of taking every imposition of excessively harsh called 'social vaccination'. We, in India, precaution against getting infected measures such as lockdowns can be have the advantage of being able and, by corollary, minimising the minimised (see Box 4). Bringing about to make use of our institutional and chances of spreading the infection the kind of behavioural changes needed cultural memory of similar, and very to others.

Key takeaways

• Epidemiologists use two approaches to control the spread of a new infectious disease — reducing its incidence, and controlling its human-to-human transmission. • Controlling the extent and rate at which the infection spreads requires an understanding of the modes (context and vehicles) of transmission. • Mitigation measures are aimed at ‘flattening the epidemic curve’ by preparing healthcare systems for the challenge of minimising spread of infection and reducing mortality. • While physical distancing minimises the context of transmission, wearing masks can minimise contact with the vehicle of transmission. • Encouraging reverse quarantines of people most vulnerable to severe forms of disease, as well as competent and correct diagnoses and treatment of severe symptoms can reduce mortality. • Governments are responsible for ensuring access to accurate understanding of the problem, as well as education and facilitation of behavioural changes involved in effective mitigation. • Each individual has the responsibility of taking precautions against getting infected and spreading it to others.

Note: Source of the image used in the background of the article title: https://pixabay.com/illustrations/physical-distancing-social-distancing-4987118/. Credits: Ramdlon, Pixabay. License: CC-0.

T Jacob John is a retired Professor and former Head of the Departments of Clinical Virology and Microbiology at Christian Medical College (CMC) Vellore, Tamil Nadu, and was Director of the ICMR’s Centre of Advanced Research in Virology. Credited with establishing India’s first diagnostic virology laboratory, Dr. John’s model of polio control in Vellore and the North Arcot district of Tamil Nadu inspired the global polio eradication initiative.

68 — Rediscovering School Science | Oct 2020 SNIPPETS

HOW EFFECTIVE ARE PHYSICAL DISTANCING, WEARING MASKS, & USING EYE PROTECTION IN CURBING SARS-CoV-2 INFECTION?

Can physical distancing, wearing masks, and using as the viruses that cause these diseases have very similar eye protection really protect us against SARS-CoV-2 modes of transmission. infection? In a study published in early June in The Lancet, To understand the findings of the study, imagine a scenario an international consortium of scientists found that where one person in a group of 100 people, mingling freely all of these interventions are effective in reducing the with each other at a social gathering, is infected with transmission of the virus by several fold, although none SARS-CoV-2. According to this study, if everyone in this offer complete protection. group maintained a physical distance of 1 m or more, only An international consortium of scientists from Argentina, ~3 out of those 100 are likely to contract the infection. In Canada, Chile, China, Germany, Italy, Lebanon, Poland, contrast, if this physical distancing is not maintained, ~13 and the United Kingdom (UK), called the COVID-19 out of the 100 are likely to contract it. Analysis suggested Systematic Urgent Review Group Effort (SURGE) study that the chances of viral transmission was likely to fall group, examined the effectiveness of different measures even more drastically if a physical distance of 2 m or more (or ‘interventions’) being used worldwide to curb the is maintained. It also indicated that wearing face masks transmission of the SARS-CoV-2 virus. The interventions reduces the chances of a person contracting COVID-19 by that were analysed included physical distancing of 1 m or a factor > 5, and wearing eye protection such as goggles more, wearing face masks (like N-95 respirators, disposable or face shields reduces transmission of the virus by a factor surgical masks, or reusable 12-16-layer cotton masks), and of ~3 (Figure 1). Finally, it showed that N95 masks were wearing eye protection (like goggles or face shields). The more effective than surgical masks, which in turn were results of this study were obtained through meta-analysis. more effective than reusable multilayer cotton masks, in Meta-analysis is a study design that uses information preventing SARS-CoV-2 infections. However, all three types from already published sources or previous research to of masks offered more protection against COVID-19 than better understand broad patterns in a particular field or single-layer cotton masks. for a particular question. For example, this study used data from a total of 44 published studies, involving These results show that while current public safety 25,697 patients from 10 countries (Saudi Arabia, China, guidelines regarding physical distancing, face masks, USA, Canada, Vietnam, Taiwan, South Korea, Germany, and eye protection are effective in curbing transmission Singapore, and Thailand), across three continents, in both of SARS-CoV-2 infection, none of them are fool-proof. community and healthcare settings. This data was not just Other basic measures such as frequent hand washing, not on COVID-19, but also on SARS (severe acute respiratory touching the face with unwashed hands, and minimizing syndrome) and MERS (Middle East respiratory syndrome), travel are also important to reduce spread of the infection.

— Rediscovering School Science | Oct 2020 69 Fig. 1. Physical distancing, face masks and eye protection are effective in limiting COVID-19 transmission, but not completely. The risks of transmission without and with the different interventions are provided in percentages. Since these percentages are only estimates, the authors use the term ‘certainty of evidence’ as a measure of how sure they are that the true effect is very close to their estimated effect. This does not mean that these interventions are not effective in curbing viral transmission. What it means is that the extent of the effects may be much higher or lower than these estimates. Credits: https://www.eurekalert.org/multimedia/ pub/233365.php. License: Creative Commons Attribution IGO (CC BY 3.0 IGO).

Notes: Source of the image used in the background of the article title: https://pixabay.com/photos/covid19-coronavirus-corona-virus-5051314/. Credits: TRDStudios / 21, Pixabay. License: CC-0.

Reference: Chu, D. K. et al. (2020). Physical distancing, face masks, and eye protection to prevent person-to-person transmission of SARS-CoV-2 and COVID-19: a systematic review and meta-analysis. The Lancet. 395. 10.1016/S0140-6736(20)31142-9.

Anusha Krishnan is a part-time science writer and editor, and a full-time mum. She loves writing about new scientific discoveries, and believes that the art of storytelling is crucial for successful science communication.

70 — Rediscovering School Science | Oct 2020 OUR RESPONSE

COVID-19 IN

RURAL INDIA SURANJAN BHATTACHARJI

How quickly is COVID-19 e have all experienced huge Brought in by international travelers, expected to spread in changes in our lives as a the infection was initially concentrated rural India? What does Wconsequence of the COVID-19 in cities with international airports the epidemic mean for pandemic. Who would have thought and dense populations. But it has now that a tiny virion, approximately 120 spread into rural areas. From the middle education in rural areas? nanometers (a hydrogen atom is 0.1 of May 2020, a third of the patients How do we empower nm) in diameter would bring the whole in Andhra Pradesh and 80% of the ASHA workers in our fight world to its knees in just a few months? positive cases in Odisha were from against the epidemic? By the second week of September 2020, the rural areas. 70% of cases in Bihar What are some of the more than 28 million people have been were in migrant workers. The spike in unique challenges and reported to be infected worldwide, and a cases in the rural areas is not yet as opportunities that rural little less than a million have died. In our big as that in the Metro cities, but it is areas present with respect own country, more than 4 million people certainly increasing. About 66% of our have been reported to be infected, and population lives in rural India, and it has to community and public been estimated that 25% of the total health initiatives? more than 75,000 people have died. These numbers represent the tip of the infections by the end of July 2020 are iceberg. The actual number of infected likely to be in our rural population. persons may be five times larger. The According to the census of India 2011, pandemic has also unleashed devastating more than 450 million Indians (or 37% economic and social upheaval. of our population) are internal migrants

— Rediscovering School Science | Oct 2020 71 who move away from their homes outbreak in 2019. This enabled the Responding to rising in search of a living. The nationwide state government to quickly deploy lockdown instituted to control the resources, and put up a timely and COVID-19 cases in rural spread of infection resulted in a sudden comprehensive response to COVID-19 areas loss of income for these guest workers in collaboration with key stakeholders. It is now established that physical in big cities. The mass migration of about For example, this involved setting-up distancing, wearing masks, washing 25 million guest workers, forced by district control rooms for surveillance, hands, and avoiding the three Cs are circumstances of the lockdown to head monitoring, widespread communication important elements in preventing back home from the cities, may have of risk and safe practices, identification the spread of the virus. The use of fueled the rapid rise in rural infections. and isolation of infected persons, masks becomes critical wherever Poor health care resources in our contact tracing and quarantine. It also congestion (within homes, in market rural areas will make testing, isolating included the design of measures to places, or while using public transport) patients, and quarantining their contacts address physical and psychosocial needs makes it difficult to practice physical with COVID-19 challenging. of vulnerable populations. This strategy distancing. Multilayered homemade worked because of the state’s long-term cloth masks protect the wearer from Before we explore options for responding emphasis on education for women, catching the infection from others, to this challenge, let us look at some systematic investment in strengthening while also preventing them (even as inspiring examples of appropriate health infrastructure and capacity asymptomatic carriers) from spreading responses to crisis and disaster. building of frontline health workers, and the infection to others. It is important strong community engagement. that the mask fits well, and covers the Learning from responses nose and mouth adequately. The third example is that of Japan’s to crisis and disaster response to the epidemic. Japan It is very important to protect the The first example is that of Odisha’s is a crowded country, with a large elderly (> 65 years old), and those response to cyclones. In 1999, a super- population of about 126 million people suffering from chronic diseases (like cyclone ravaged Odisha and close to and a high proportion of elderly people asthma, diabetes, hypertension, heart 10,000 people died. Last year, cyclone (25.9% above the age of 65 years). failure, or cancer) from infection. This Fani affected 16.5 million people in As of the second week of September can be achieved by cocooning or reverse Odisha, but less than 50 lives were lost. 2020, they have reported only 74,544 quarantining them in their homes. How did this transformation occur? The COVID-19 cases and 1423 deaths. What does this mean? Normally, people state government set up its own disaster What is interesting is that they have with an infectious disease are isolated, management system as an autonomous succeeded in limiting their numbers and their close contacts quarantined body to combat emergencies. It without following the WHO’s dictum to prevent spread of the illness. In developed appropriate technology of test, test, test, and without a strictly contrast, a reverse quarantine approach to send 18 million SMS messages to enforced lockdown or closed borders. quarantines uninfected but vulnerable prepare citizens with rules to follow What they did do is to encourage people people to protect them from contact during the cyclone Fani. It mobilized to avoid the three ‘C’s: closed spaces with infected people. Each community the local administration, police, and with poor ventilation, crowded places will need to provide quarantined people volunteers to go from house to house, with many people, and close contact with physical support (by supplying and evacuate 1.8 million people to such as face-to-face conversations. provisions like rations, water, food, the more than 9000 shelters that Japan used a cluster-based approach or medicines) as well as psychosocial had been prepared. What an amazing to testing, testing clusters of rapidly support (to prevent depression from the transformation in 20 years! spreading infection, rather than testing prolonged isolation). the whole population. The Japanese The second example is that of Kerala’s Social occasions like birthdays, government declared a national response to the epidemic. The first weddings, funerals, as well as collective emergency, but allowed some economic positive case of COVID-19 in our worship in temples, mosques, and activities, like in factories, to continue. country was reported from Kerala in churches will need to be postponed, They did not order people to stay at January 2020. Since then, in a state avoided, or curtailed in such a way that home, wear masks, or wash their hands. with 35 million people, as of the second only the fewest people attend. Physical But, by and large, that is what most week of September, there have been a contact among even those who attend Japanese people did. lakh cases, 440 deaths, and a recovery needs to be minimized by ensuring rate of 71.7%. The state’s remarkable How can learnings from these and staggered timings and 2 m (or 6 feet) success is attributed to learnings from other such examples help us address the physical distancing. Large gatherings their earlier experience of the Kerala anticipated increase in COVID-19 cases in movie theatres, public meetings and floods in 2018, and the Nipah virus in our rural areas? rallies, or festivals, melas, and thiruvizas

72 — Rediscovering School Science | Oct 2020 need to be avoided altogether. Essential address systems. The possibility of workers, who are at the bottom of services like hospitals and clinics will setting up solar cells and batteries, or the health provider’s pyramid, are need to move their waiting spaces micro-hydroelectricity generators can the foundation and basis of our outdoors, to well-ventilated shelters be explored in areas where electricity healthcare workforce. The strength or under the shade of a tree, rather is not available. Before the epidemic and effectiveness of the entire health than in a crowded, closed, indoor overruns an area, high school and service depends on them. Rather than space. Wherever possible, medical college students can be empowered to being empowered and strengthened, and pharmacy services will need to be take these ideas forward by building they are often weakened by delays provided at the patients’ doorstep. on pre-existing expertise. In some in paying their meagre salaries (for villages, teachers or volunteers visit their example, in some states, their salaries Since March, schools and colleges students to provide emotional support have not been paid since February). have shut down completely. Some and encouragement, and distribute Their already full work schedules have teachers are borrowing amplifiers rations from the midday meal scheme been increased exponentially during and loudspeakers to take their classes (so that the children do not go hungry). the epidemic. These workers are now outdoors, under trees, with their pupils involved in contact tracing, watching spread out to ensure 2 m distance The shortage of medical infrastructure for symptoms of fever and cough in between any two of them. Other could be imaginatively addressed the community, supervising home teachers are using smart phones for by turning village schools, colleges, quarantines, counselling relatives online classes in towns where computers and other such buildings into of patients, delivering groceries, are not available. Access to this form of temporary quarantine shelters for food and medicines to families from learning can be improved by subsidizing housing contacts. While rapid testing common kitchens, etc. Often, they are broadband charges in rural areas, technology is being developed and expected to carry out these additional and providing second-hand smart mass produced, community health responsibilities without appropriate phones to students' families. Other workers can be taught how to clinically training and PPE (personal protection options that are being explored for diagnose COVID-19 syndrome as equipment). This needs to be addressed local connectivity include educational described by Professors M S Seshadri on a war footing. television programmes and community and Jacob John (see Jacob T. John's radio programmes. Rajasthan’s ‘Apno article titled 'Mitigation of the Radio’ as well as Maharashtra’s COVID-19 Epidemic' in the same issue). Parting thoughts ‘Vidyavani’ and ‘Vasundhara Vahini’ Providing every health centre with Gandhiji envisioned a future where are good examples of the latter. Where portable oxygen concentrators, which our villages developed into healthy, even this is not available, older children can extract nitrogen from atmospheric self-sufficient units without the can be encouraged to teach their air, will help make oxygen available dehumanization that seems inevitable younger siblings in an ‘each one, teach for patients with mild symptoms of at the much larger scale of cities. The one’ manner so that learning is not breathlessness. Together, these measures COVID-19 epidemic is an opportunity to interrupted. These methods can also will enable the treatment of nearly make that dream come true. While the be used to spread the message that 90% of people infected with COVID-19 world is waiting anxiously for a vaccine keeping physical distance, wearing in villages. Less than 10% of infected against SARS-CoV-2, it is vital to utilize masks, washing hands, practicing people would need to be transported the vaccine that we already have in cough etiquette, giving up spitting and to medical centres outside the village. our hands — education against the smoking, and encouraging non-contact The workforce for supervision of these virus of panic, selfishness and violence greetings are needed to effectively treatment centres could be enhanced by that has tragically accompanied the ‘break the chain of transmission’. engaging the services of unregistered, COVID-19 pandemic. We can overcome This could also be a time to address informal health workers. These health this adversity by learning how to infrastructure gaps. For example, the workers could be trained to use clinical bridge gaps and prepare for disasters infrastructure for digital communication guidelines and protocols for COVID-19, from past mistakes; making long-term can be improved through the use of as has been done successfully in the investments in public education and temporary cellular towers or balloons, case of childhood pneumonia. It is health infrastructure; and building trust, and the introduction of community important to remember that ASHA confidence, and mutual respect within radio or battery-operated public- (Accredited Social Health Activists) our communities.

— Rediscovering School Science | Oct 2020 73 Key takeaways

• The rapid rise and spread of COVID-19 infection in rural India may have been fueled by the return of guest workers from big cities to their homes as a result of the nationwide lockdown. • Those most vulnerable to COVID-19 need to be protected through a reverse quarantine approach with appropriate physical and psychosocial support from the community. • Social and cultural gatherings need to be curtailed to the bare minimum, and gatherings for essential services need to be moved to well-ventilated outdoor spaces to minimize physical contact. • Improvements in infrastructure gaps coupled with context-dependent methods like the use of loudspeakers, smartphones, television and community radio programmes can help meet educational needs and create awareness of the disease. • Infrastructure gaps in medical services can be addressed through imaginative measures, as well as the education, training, and empowerment of formal and informal health workers. • Adversities in rural India can be overcome through learning from past mistakes, making long-term investments in public education and health infrastructure, and building trust, confidence, and mutual respect within communities.

Notes: Source of the image used in the background of the article title: https://pixabay.com/photos/lockdown-exodus-india-people-5061663/. Credits: balouriarajesh. License: CC-0.

Suranjan Bhattacharji was a former Head of the Department of Physical Medicine & Rehabilitation, and a former Director (2007-2012) at Christian Medical College (CMC) Vellore, Tamil Nadu.

74 — Rediscovering School Science | Oct 2020 SNIPPETS

WILL RINSING MY HANDS, MOUTH, & NASAL PASSAGE WITH COCONUT OIL DISSOLVE THE VIRUS ENVELOPE AND PREVENT INFECTION?

Since ‘like dissolves like’, a polar or charged substance can dissolve other polar substances, and nonpolar substances Box 1. Did you know? can dissolve other nonpolar substances. This means that The World Health Organisation (WHO) advises washing hands polar lipids can dissolve the outermost layer (called the with either soap and water, or alcohol-based sanitizers. envelope) of a coronavirus, which is made up of a fat-like Soap is currently the only recommended way to destroy the (polar) substance. Soaps can also achieve this. In other envelope of SARS-CoV-2. Sanitizers with alcohol work in a words, both polar lipids and soaps can form the “micelles” completely different manner, by damaging the proteins in that are required to dissolve and break polar phospholipid this fat layer. bilayers, like those in cell membranes and the envelope of a coronavirus. Coconut oil, on the other hand, consists only While some fats (like those in coconut oil) may have of nonpolar fatty acids, which form globules (instead of antimicrobial properties against some bacterial species micelles) when mixed with water. Even in ionised, charged in lab tests, there is no evidence that they can impact states, these fatty acids do not form micelles efficiently viruses. One study indicates that a chemical derived from due to their chemical structure. What about soaps that use lauric acid is effective against many viruses, including coconut oil as a base? The oil in these soaps is ‘saponified’, coronaviruses. While lauric acid is a major constituent or changed to a different chemical structure through a (49%) of coconut oil, this ‘antiviral’ derivative is not found chemical reaction. So applying coconut oil to one’s hands in coconut oil. So there is no evidence to suggest that would not affect SARS-CoV-2 (see Box 1). coconut oil may inactivate SARS-CoV-2.

— Rediscovering School Science | Oct 2020 75 SNIPPETS

MENTAL HEALTH OF THE ELDERLY DURING THE COVID-19 OUTBREAK

How can the COVID-19 outbreak affect What are some signs of depression in the mental health of the elderly? the elderly? The outbreak of COVID-19 could lead to greater levels Symptoms of depression in the elderly might manifest of stress in the elderly, as a result of being more at risk differently than those in younger people. For example, of the infection. It could also lead to increased feelings instead of sadness, one might feel increasingly tired. The of isolation, especially if they are already experiencing following changes may be signs of depression: conditions like widowhood, limited mobility etc. Loneliness z Physical signs: Tiredness, difficulty in sleeping, and can increase the risk for depression and anxiety. Those who changes in appetite. rely on social contact out of their homes are even more z Mood disturbances: Grumpiness, irritability, and anger. vulnerable to mental health concerns. z Cognitive signs: Confusion, memory, and attention What issues pertaining to COVID-19 problems. Thoughts of dying/suicide. Neglecting personal care. affect the mental health of the elderly more than other age groups? What can I do to help the elderly at z Difficulty in accessing help, support, and resources as home showing such symptoms? care-givers are unable to travel and meet them. The following steps can help the mental well-being of the z Difficulty in connecting with others through social elderly: media and technology such as mobile phones, skype, z Doing activities together, like looking at old photos, Zoom etc. listening to music, or playing a game. z For those who have health complications and age- z Ensuring that there are enough small chores that they related disabilities, any disruptions in access to ongoing can be part of, and can contribute to. constant medical care due to the pandemic may affect their mental health too. z Helping them reconnect with others using technology. z A regular schedule of exercise, and exercising together. What are some signs of mental health z Reassurance and validation of mental health concerns as concerns in the elderly during this a result of the pandemic. time? In the presence of mental health concerns of greater severity, We might observe a range of mental health concerns one might not be able to utilize typically healthy coping including: mechanisms. In such instances and in the absence of support, it is strongly recommended to reach out for professional z Boredom and disturbances in sleep, appetite, and eating. support. z Worry and anxiety related to death, dying, illness, and uncertainty about the future. When should one get professional help? z Hopelessness and/or helplessness. The answer depends on many factors:

z Sadness, loss of interest, low levels of motivation and z Duration and course of mental health concerns: Have energy. symptoms of depression been around for a while? How In some cases, mental health concerns can develop into has the person been able to cope with concerns so clinical disorders. It is particularly important to pay far? Do they have access to support? In some cases, we attention to signs of depression and anxiety-related might see mental health concerns suddenly worsening disorders at this time. as a result of the pandemic.

76 — Rediscovering School Science | Oct 2020 z Severity of concerns: Concerns that are present most of z Motivation for self-care: Due to mental health concerns, the day, every day, might indicate greater severity. One one may not be able to access motivation to change or also needs to look for signs of risk. This would include engage in self-care. increased thoughts of dying, and not wanting to be alive.

Notes: 1. These responses were first published on the Indian Scientists’ Response to CoViD-19 (ISRC) website. 2. Source of the image used in the background of the article title: https://www.istockphoto.com/photo/quarantine-for-old-people-gm1219512973-356745103.

WILL CONSUMING DATURA PREVENT SARS-CoV-2 INFECTION?

The Datura stramonium shrub is widely distributed in Asia, motion sickness, and low blood pressure (caused by a slow Africa, and the Americas. The fact that it has spherical, heart rate). But these compounds have many adverse prickly fruit (and is, therefore, also known as thorn apple) effects. Not only are they hallucinogenic (causing people that resembles SARS-CoV-2 with its spike protein is only a to hear or see things that are not real), they can cause coincidence. There is no evidence to suggest that the plant disorientation, and a rapid, irregular heartbeat (which or any of its parts have antiviral properties. can be fatal). In fact, consuming these compounds, parts of the Datura plant, or the plant as a whole without the Parts of the Datura plant are rich in compounds (known advice of a doctor can be fatal. as tropane alkaloids) that are used as medication for

Notes: 1. This response was first published on the Indian Scientists’ Response to CoViD-19 (ISRC) website. 2. Source of the image used in the background of the article title: https://www.flickr.com/photos/99758165@N06/18652364948. Credits: NY State IPM Program at Cornell University. License: CC-BY.

— Rediscovering School Science | Oct 2020 77 OUR RESPONSE LIFE IN TIMES OF COVID-19

G. THANGAVEL, JAYAPRAKASH MULIYIL & ANOOP JAISWAL

Should vegetables Why should we be of beds, ventilators, and treating be washed with soap concerned about doctors available in hospitals, many lives that could have been saved were before using them? contracting COVID-19? Can COVID-19 spread unfortunately lost. This means that even Since the SARS-CoV-2 virus, which if it is not very virulent (or deadly), the from newspapers, coins, causes COVID-19, is a brand-new virus, virus can wreak havoc if the speed at bank notes, ATM cards, none of us have specific immunity which it spreads is not controlled. or air conditioning? against this virus. When a new virus is Do Indians have innate introduced into a community, everyone How quickly does the immunity against SARS- has the same chance of getting infected. When there are no control measures in SARS-CoV-2 virus spread CoV-2? How do we use in a human population? herd immunity to our place, a large number of people may get infected in a short period of time. If Epidemiologists use a parameter called advantage? the number of people infected with the basic reproduction number, denoted virus begins to increase exponentially, as R0 (pronounced as R naught), to the number of patients with serious determine the initial speed with which a illness at a given point of time will begin virus spreads in a susceptible population to exceed the capacity of hospitals when no preventive measures are in to treat them. This can result in many place. This number is defined as the deaths. We have seen this happen average number of people that can in Wuhan (China), Lombardy (Italy), get infected from a single infected and Indore (Madhya Pradesh, India). individual. The R0 for SARS-CoV-2 is Since the number of people needing estimated to be around 2.5 to 3. This hospitalization exceeded the number means that an infected person would,

78 — Rediscovering School Science | Oct 2020 on average, transmit the virus to about Diseases like measles infect a greater respiratory droplets and direct contact. three people in a vulnerable community. proportion of people (over 80%) before However, a possibility for airborne Although this virus does not produce they die down. It is estimated that about transmission exists in clinical care serious disease in a majority of people, it 40-60% of people would need to be settings when procedures or support is still a highly contagious one. infected before the current COVID-19 treatments that generate aerosols are performed. In non-clinical settings, Three factors determine the value of R0: epidemic reaches this stage. Until this number is reached, the epidemic, if left the possibility of aerosol generation z The infectivity of the virus (or the unchecked, can result in the deaths of generally does not exist, and hence ability of the virus to infect a healthy thousands of people. airborne transmission is unlikely. individual), When people keep a safe distance from z The duration of infectivity of the Can air conditioning virus (or how long the virus can remain each other, it decreases the chances of infective), and, the virus spreading from one person spread the infection? to another. This measure, referred to Sensing the plausibility of air borne z The number of uninfected people as ‘breaking the chain’, reduces the transmission, various Heating who are in contact with the virus at a speed of transmission (denoted as Rt) Ventilation and Air Conditioning given time. of the epidemic. Rt is defined as the (HVAC) federations and societies The first two factors are virus-dependent ‘effective reproduction number’ at any in different countries, including and, therefore, non-modifiable. In other given time. With the implementation India, have come up with guidelines words, we don’t have control over these of preventive measures, and as more on HVAC operations during the factors until we find a medicine or people develop immunity against the COVID-19 pandemic. For residential vaccine against the virus. But the third virus, Rt becomes lesser than R0. air conditioners, recirculation of cool factor is dependent on us, and can be air must be accompanied by outdoor controlled. Reducing the number of Remember, this process does not cause air intake through slightly opened susceptible people who are in contact the virus to go extinct. However, as windows. This guideline is applicable with an infected person at a given point its speed of the transmission is greatly if someone at home is infected and in time can help stop the virus spreading reduced, the virus will take many more they are in isolation in a room fitted at a breakneck speed. months to infect the proportion of people with an A/C. For public spaces with needed for it to spontaneously stop. centralized air-conditioning, A/Cs What do the terms ‘breaking This reduced rate is called 'flattening the fitted with the provision of fresh the chain’ and ‘flattening curve'. Since this process reduces the air intake should be operated. If the number of people infected at any given the curve’ refer to? centralized air conditioning system point in time, it decreases the load on does not have an inbuilt fresh air If left uncontrolled, any new viral hospitals during the time the infection is intake provision, opening operable infection would spread exponentially spreading in a particular community. windows is recommended. However, in a community as no one would these operational guidelines of HVAC be immune to it. In a few months, What are the most are effective only when combined with a ‘substantial proportion’ of the more reliable prevention measures population would have been infected. important ways in which such as physical distancing, frequent At this stage, there would be very SARS-CoV-2 infection is hand washing, wearing masks, and few people who have not developed transmitted? sanitization of the flooring in offices immunity against the virus through Respiratory infections can be and public places. prior infection (the exhaustion of transmitted through droplets of susceptible persons). This would cause different sizes. Droplet particles that Can we catch COVID-19 the number of new infections to drop are > 5-10 μm in diameter are referred with the same speed with which it to as respiratory droplets, while those from the non-respiratory had started. This drop would happen that are < 5 μm in diameter are referred body fluids of an infected without any intervention (such as to as droplet nuclei. Due to their person? medication or vaccination). heaviness, droplets quickly settle down, Although virus particles have been The substantial proportion of a but droplet nuclei can remain in the air detected in the blood, stool, and semen population that needs to be infected to for long periods of time. These nuclei of infected people, it is not yet known reach this point varies with each viral are prone to airborne transmission over whether non-respiratory body fluids infection. For example, H1N1 (Swine distances > 1 m. According to current from an infected person including flu) in 2009 infected 40% of people evidence, SARS-CoV-2 virus is primarily vomit, urine, breast milk, or semen can before it subsided in the first wave. transmitted between people through contain viable, infectious SARS-CoV-2.

— Rediscovering School Science | Oct 2020 79 How do we handle the places (some from Kerala), got infected. stages of the epidemic in India led to dead body of a person who But contact tracing did not reveal a a number of claims that Indians may single case that had spread through the have some innate immunity against has died of COVID-19? vegetables sold in the market. COVID-19. This was called the Indian As the dead body does not have any paradox — since Indians are already physiological function, such as coughing Can COVID-19 spread afflicted with many infectious diseases, and sneezing, the chance of getting from newspapers, coins, we may have some immunity against infected from droplets is absent. Only COVID-19. But, now, these claims have the lungs of dead COVID-19 patients, bank notes, or ATM cards? been proven wrong. If anything, the if handled during an autopsy, can be So far there is no epidemiological fact that India has so many infectious infectious. The clothes of the dead body evidence for this kind of transmission. diseases is a reflection of the poor state might also harbor the virus. In this Therefore, one need not be too alarmed. of public health in India! regard, refer to the Ministry of Health However, it is always sensible to take and Family Welfare, Government of precautions like washing hands with Why is India reporting one India, guidelines. soap as frequently as possible. of the lowest COVID-19 mortality rates? Yesterday, when I was What is the risk of getting COVID-19 from packages Differences in number of cases and buying vegetables from deaths could be caused by several a nearby shop, someone delivered through the factors. They could be related to unknowingly came very postal system? different phases of the epidemic in close to me. Should I Studies have established the presence different countries, or differences in worry? of SARS-CoV-2 virus on cardboard for demography, local environment and 24 hours under experimental settings people’s behaviour in each country. No. Although people catch the virus in controlled environments. In practice, They could also be influenced by how from their contacts, casual contact of however, there is no evidence of the different governments implement this kind is unlikely to spread the disease. infection being transmitted through control and mitigation strategies and, Epidemiological research shows that contaminated packages. most importantly, how each country disease transmission occurs in people who defines and counts cases and deaths. have reported sustained close contact Therefore, one cannot (and should not) for longer periods of time in closed or We don’t have much space in our house. How can blindly compare the number of cases crowded places. In fact, a study from and deaths in different countries in the the United Kingdom found that casual we ensure the physical middle of a pandemic. talking in an open or semi-open space distance needed to keep did not lead to disease transmission. our elderly parents from How do we use herd Should vegetables be catching the virus? immunity to our advantage? washed with soap before This has to be worked out at the level All infectious disease epidemics can of each family. The more distance come to a spontaneous stop when using them? young people maintain from the elderly, a substantial proportion of the It is always advisable to wash vegetables the lesser the chance that the latter population has either been infected in running water. But washing them in contract the virus. Even simple measures with the pathogen, or is vaccinated soap water is not advisable as this may can help. For example, allocate a chair against it. In both cases, people with produce other unwanted side effects. It exclusively for the elderly father or antibodies against the pathogen attain is important to keep in mind that while grandparent, and request everyone else immunity against infection. For viral there is a theoretical possibility of the in the family to refrain from using that. infections, immunity acquired through virus spreading through vegetables, During summers, one can sleep outside natural infection is, in general, stronger there is no epidemiological evidence for the house, etc. (even lasting lifelong) than vaccine- it. For example, Koyambedu market, the induced immunity. Once a particular largest wholesale market for vegetables, Indians have a lot of community attains this threshold fruits, and flowers in Chennai, was innate immunity. Will stage, it is said to have acquired herd recently identified as a hotspot for immunity. At present, there are no COVID-19 spread. Thousands of people this protect us from vaccines available against COVID-19. associated with the market, such as COVID-19? Hence, to acquire the herd immunity vendors and load men from faraway The low number of cases in the initial needed for the epidemic to die down

80 — Rediscovering School Science | Oct 2020 However, this natural process can work to our advantage if we protect our elderly and other vulnerable people from catching the virus through reverse quarantines (see Fig. 1). The rest of the population can resume work with proper physical distancing measures in offices and public spaces. Through this strategy, young and healthy individuals will continue to get infected, but gradually. Remember, the chance of experiencing severe disease increases with age. Most young people (<60 years of age) who get infected are likely to be asymptomatic or experience mild disease. Measures to slow down spread of infection will help ensure that the few young people who develop severe disease can be saved by Fig. 1. What is a reverse quarantine? Isolation and quarantine of infected people and their proper medical attention. Over time, contacts are used to minimize their ability to transmit infection to healthy people. In contrast, reverse quarantines are used to protect the elderly and other vulnerable people from catching this young population (about 85% of the infection from others. people in India are below 60 years of Credits: Adapted from an image by A.V.Raveendrana & Rajeev Jayadevan in ‘Reverse quarantine and age) will contribute to building herd COVID-19’, Diabetes & Metabolic Syndrome: Clinical Research & Reviews (2020), 14 (5): 1323-1325. immunity, while the vulnerable remain URL: https://doi.org/10.1016/j.dsx.2020.07.029. protected. Thus, if we follow this strategy, we will be able to overcome in the first wave, about 40-60% of the distancing in place, this will eventually the epidemic with fewer deaths. It is people (depending on the population happen, albeit slowly. Therefore, herd obvious that this will be a long process. density of the area) will need to get immunity is a natural process, not a But, in the absence of a vaccine or infected. Even with proper physical strategy to overcome epidemics. medicine, it is the best way forward.

Key takeaways

• Mitigation measures reduce number of deaths by ensuring that the number of patients with serious illness at a given point of time does not exceed the capacity of hospitals to treat them. • Physical distancing reduces the chances of the virus spreading from one person to another (breaking the chain) and the speed of transmission of the epidemic (called ‘flattening the curve’). • It is not yet known if non-respiratory body fluids from an infected person including vomit, urine, breast milk, or semen can contain viable, infectious SARS-CoV-2. • The lungs and clothes of dead bodies of infected people can be infectious or harbour the virus. • There is no epidemiological evidence to show that the virus spreads through vegetables, newspapers, coins, bank notes, ATM cards, or postal packages. But it is sensible to take precautions like washing vegetables with water, and hands with soap as frequently as possible. • Initial claims that Indians may have some innate immunity against COVID-19 have been proven wrong. • The natural process of herd immunity can be used to our advantage if we reverse quarantine the elderly and other vulnerable people, while the rest of the population resumes work and follows proper mitigation measures in offices and public spaces.

— Rediscovering School Science | Oct 2020 81 Notes: 1. These questions and responses were first published in an open-access booklet calledUnderstanding the Pandemic COVID-19, authored by Dr. G. Thangavel, Dr. Jayaprakash Muliyil & Anoop Jaiswal, that has been translated into several Indian languages. 2. Source of the image used in the background of the article title: https://en.wikipedia.org/wiki/File:Safe_Newspaper_Vendor_-_coronavirus.jpg. Credits: Vaikunda Raja, Wikimedia Commons. License: CC-BY-SA.

G. Thangavel works as an Assistant Professor of Epidemiology, in the Department of Environmental Health Engineering, Faculty of Public Health, Sri Ramachandra Institute of Higher Education and Research (Deemed University), Chennai, Tamil Nadu. Jayaprakash Muliyil retired as a Professor of Epidemiology, Department of Community Health, and Principal of Christian Medical College (CMC) Vellore, Tamil Nadu. Anoop Jaiswal works as the Secretary, Theosophy Science Centre, Theosophical Society, Chennai, Tamil Nadu. SNIPPETS

Science Webinars for Young Minds

For children (6-16 years) Weekly, One hour of live interaction (Mondays 5-6 pm IST) Content curated by scientists New Scientific Topic each week COVID-19, Microbes in Food, Vaccines, Human Cells, Antibiotics, DNA and Heredity, Biotechnology, Tuberculosis, Dengue Fever, Peafowl behaviour, Immunology, and more! Also, Guest Scientists and Hands-on Sessions Please join and share! Sample flyer

https://twitter.com/TTASIndia https://www.karishmakaushiklab.com/talk-to-a-scientist

https://www.facebook.com/TTASIndia/ [email protected]

Talk to a Scientist is a unique science outreach platform in India that uses an interactive webinar format to share science with children (6-16 years). Founded by two scientists, Dr. Karishma S Kaushik and Snehal Kadam, these ongoing weekly sessions cover a range of science topics with content curated by the scientist-founders themselves, and also include guest scientists and hands-on sessions. Funded by the first IndiaBioscience Outreach Grant, the platform aims to make science accessible and engaging to children across India, and build Indian science role models. The sessions are open to all, so please join and share!

82 — Rediscovering School Science | Oct 2020 SNIPPETS

SCIENCE CAN BE MORE FUN THAN FUN

Work is more fun than fun. — Sir Noël Peirce of us have to be content with being mere consumers Coward, playwright, composer, director, actor and of knowledge. Everyone, especially young students and singer (1899-1973). amateur scientists, can become producers of knowledge in science. But there is only so much that a passive column The supreme accomplishment is to blur can accomplish. As teachers having the privilege and the line between work and play. — Arnold J. responsibility of shaping young minds, you can of course Toynbee, historian (1889-1975). do much more, and hence this message to you. Why is science not always perceived as fun and play? Box 1. Check out: Surely, it ought to be. Part of the problem, I believe, is that we think of science too narrowly. What is science, 1. My column 'More Fun Than Fun': what is the scientific method, who should practice science, • In English: https://science.thewire.in/the-sciences/ when, and for what purpose? We tend to answer all these more-fun-than-fun-science-stories-raghavendra- questions very narrowly and very conservatively. We gadagkar/. think of science as complicated and difficult to pursue, • In Kannada: https://science.thewire.in/the-sciences/ to communicate, to teach and, therefore, to learn. This is raghavendra-gadagkar-column-kannada-podcast- a great shame, and needs to change. I am endeavouring kollegala-sharma-janasuddi/. to make a small contribution toward such a change by • Narrated by Dr. J. R. Manjunatha in the daily writing a regular column for the online portal The Wire Kannada science podcast “Janasuddi”: https://anchor. Science. As a first step, I have called my column 'More Fun fm/kollegala/episodes/4-1-ek0ils/. Than Fun'. My articles are being translated into Kannada by 2. Shri Kollegala Sharma’s article 'Why does science Shri Kollegala Sharma. The Kannada text is published in The communication excite me?': https://indiabioscience.org/ columns/opinion/why-does-science-communication- Wire Science, and is being narrated by Dr. J. R. Manjunatha excite-me. in the daily Kannada science podcast “Janasuddi”. It is my hope to inspire students and teachers to change our 3. My answer to the question posed by the French Academy of Sciences on their 350th birthday: https://insa.nic.in/ perception of science. writereaddata/UpLoadedFiles/PINSA/2016_Art109.pdf. In each short article, I try to show three things. First, 4. Alison Gopnik’s book The Gardener and the Carpenter: science is fun. Second, almost anybody can practice https://us.macmillan.com/books/9781250132253. science. Third, that science can contribute to all spheres of human knowledge. I also focus as much on the process On their 350th birthday, the French Academy of Sciences of science as on its products because I believe that the invited the presidents of many science academies across journey is more important than the destination. I am the world to address the following question: 'What tools trying to convey the message that science is not just a do we need to understand the universe?'. My answer was set of ready-made gifts that scientists offer to the rest of that we cannot predict the future of the universe and, the world. Instead, science is a way of life that we can all therefore, we cannot know what tools we will need in the practice, and be both happy and wise. Through examples future. All that we can and need to do is to nurture the of scientific research that almost anyone armed with human mind, the minds of future generations of humans. curiosity and a spirit of adventure could have done, even This is the single most important tool that will allow us without sophisticated laboratories and big grants, I hope to invent and construct whatever other tools we might to democratise science. It is my hope to show that none need at any time in the future, to face any contingency,

— Rediscovering School Science | Oct 2020 83 good or bad, pleasant or otherwise. And the “we” here refers in science education. Gopnik’s advice is that we should primarily to teachers. not be like carpenters — shaping children to fit the model of an adult that we have in mind. Instead we should be Our present system of education is, however, rather flawed like gardeners — providing a protected and nurturing — we feed students with facts rather than teach them environment for children to flourish and realize their how to think. We destroy their curiosity and creativity, and potential. This was her advice for parents, but I think it is replace them with ‘knowledge’. Sometimes I find that the even more apt for teachers. less educated a student is, the brighter and more intelligent she is; the more likely to be able to solve problems de Whether as science teachers, communicators, or researchers, novo. I often joke that I have to ‘cure’ my students of their we must ponder the words of Glenn T. Seaborg, scientist, education, before I can nurture them into thinkers and Nobel laureate (1912-1999): “There is a beauty in discovery. problem solvers. You have the power to change this. In her There is mathematics in music, a kinship of science and book entitled The Gardener and the Carpenter, the child poetry in the description of nature, and exquisite form in a psychologist Alison Gopnik laments our over-emphasis on molecule. Attempts to place different disciplines in different goal-directed 'Exploit Learning', and our neglect of playful camps are revealed as artificial in the face of the unity of 'Explore Learning'. Nowhere is this more damaging than knowledge”.

Note: Source of the image used in the background of the article title: https://pxhere.com/en/photo/340995. Credits: Papa Pic Free, Pixabay. License: CC-BY.

Raghavendra Gadagkar is DST Year of Science Chair Professor, Centre for Ecological Sciences, Indian Institute of Sciences (IISc), Bangalore. He can be contacted at: [email protected].

84 — Rediscovering School Science | Oct 2020 Write for us We invite i wonder... is a magazine for school science teachers. submissions of proposals If you have an idea for an article that is linked to the school science for our theme — curriculum or teaching practice, please send a brief overview (< 500 words) or TEACHING AS IF THE a draft (1500 words) with your bio (< 30 words) to us at [email protected]. EARTH MATTERS Your submission can be in the form of a perspective piece, teaching reflection, activity ideas, concept builders, or stories that explain scientific concepts. We also invite questions that you'd like our editors to respond to. We accept submissions in English, Hindi, and Kannada. Recurring sections:

The Science Lab Tried-and-tested thought/practical experiments to teach a concept Life in your Backyard Concepts and activities to use one’s immediate surroundings for ecological literacy

Annals of History The history of one major scientific idea/innovation/concept

Biography of an Environmental Her life and times through the prism of her contribution to science Scientist The Science Educator at Work Narratives of your experiences as a teacher in the science classroom

Book Review Review of a book that can contribute to the teaching/learning of school science

Hot off the Press Why recently reported scientific/educational research has grabbed headlines

Can’t find a match? Get in touch with us. We’ll help identify the section that your article fits best.

Have a short (200-400 A special invitation to practicing science teachers and teacher words) SCIENCE SNIPPET educators: we are looking to feature methods, activities, and examples on some funny, fascinating, you’ve tried and tested in your classrooms to engage the curiosity and mysterious, or inspiring facet imagination of your young learners. of science or scientists? Send it to us with a short bio and a photo of yourself — the five best submissions will be Ideas for POSTERS (< 600 words) or ACTIVITY SHEETS that teachers can published in our next issue. directly use in their classrooms are particularly welcome!

Proposals for articles for the theme section need to reach us latest by 31st Dec, 2020, while those for our recurring sections are accepted throughout the year.

Printed and published by Manoj P on behalf of Azim Premji Foundation for Development. Printed at Suprabha Colorgrafix (P) Ltd., No. 10, 11, 11-A, J.C. Industrial Area, Yelachenahalli, Kanakapura Road, Bangalore 560062. Published at Azim Premji University, PES College of Engineering Campus, Electronics City, Bangalore 560100. Editors: Ramgopal Vallath, Chitra Ravi & Radha Gopalan

— Rediscovering School Science | Oct 2020 85

Common Myths about Microbes

Author: Somdatta Karak

Are bacteria and viruses very different? Are we at war with microbes? Are all microbes evolving ways to infect and kill us? Too tiny to be seen, microbes seem to lead mysterious lives. Let’s explore some common myths around them. MYTH 1 What we can’t see doesn’t exist.

FACT While microbes can’t be seen with the naked eye, they are visible under microscopes. Depending on how small a microbe is, you may need a light/ electron microscope to ‘see’ it.

MYTH 2 Microbes are microbes. They are all one.

FACT Microbes come in different shapes and sizes. We group them as bacteria, viruses, protozoa, fungi, and algae (although some fungi and algae are too large to be called microbes). MYTH 3 All microbes are bad for us.

FACT Calling microbes ‘good’ or ‘bad’ does not do justice to the many ways in which they interact with us, some of which we are just beginning to understand. For example, microbes like the Lactobacillus helveticus in our gut help regulate our mood and metabolise food. We need some microbes (like rhizobia and mycorrhizae) to keep soil fertile enough to grow food, and others to prepare yoghurt, bread, and idlis.

Do you know the names of the microbes that help us prepare yogurt, bread, and idlis?

Some, like the cold virus in humans, always cause disease. Others cause disease under specific conditions. For example, Escherichia coli is helpful in our gut, but can cause a lot of pain in the urinary tract. Some disease-causing microbes help protect food crops from insects and weeds. For example, the Tussock moth virus infects and kills Tussock moth caterpillars that would otherwise feed on potato, tea, and castor plants. Also, many microbes seem neutral to us — we haven’t found them helpful or harmful yet.

Would you call Escherichia coli good, bad, or both? MYTH 4 The same drugs can kill all microbes.

FACT No, they can’t. For example, antibiotics are a class of drugs that kill bacteria, but not viruses. Even with bacteria, different antibiotics act in different ways. Some antibiotics can only kill bacteria from certain families, while others can kill bacteria from a wide range of families.

MYTH 5 , I have a fever. I’ll just take the pill that the doctor prescribed to my mother a week back.

FACT A fever can have different causes — mostly infectious, but sometimes non-infectious. Only a doctor can help identify its specific cause. Even if it is the result of an infection, only take the medicine that the doctor prescribes for you now. Any left-over medicine from an earlier prescription for your mother (or you) might be for a different kind of microbe. For example, if your mother’s fever a week back (or your own fever a month back) was because of a bacterial infection, the doctor may have prescribed an antibiotic. If the fever you have now is because of a virus, the antibiotic will not help you. MYTH 6 Even if my cold/ fever might be because of a viral infection, I’ll take antibiotics just to be on the safe side.

FACT Remember, antibiotics won’t make a dent on the virus. But they can kill the helpful bacteria in your body, like those in your gut. So taking antibiotics may make you even more sick.

MYTH 6 Taking paracetamol kills the infection.

And they called it ‘taking a chill pill’.

FACT

You take paracetamol (like Crocin) when you have a fever only because it helps bring down your body temperature. If the fever is due to an infection, the microbe causing it can be killed either by your immune system, or other drugs that your doctor prescribes.

Do you know how long it takes for a paracetamol tablet to bring down a fever? MYTH 8 One vaccine can protect us against all kinds of infections.

FACT A vaccine is made to provide long-term immunity to a specific microbe. It contains something resembling the microbe — a part of it, or a weakened form of it that cannot cause disease. When a vaccine is introduced to our body, our immune system is activated in a way that allows it to recognise, attack, and kill the disease- causing form of the microbe more effectively. So one vaccine cannot protect us from all kinds of infections. How many vaccines do we need? We are only vaccinated against diseases that pose a serious threat to us. For example, those who were growing up in the 1960s were vaccinated against smallpox. This helped eradicate the disease, and we don’t need to get vaccinated against it anymore. Today, we are looking for a vaccine that can prevent COVID-19.

Do you know which microbes you are vaccinated against? What about your parents? And your grandparents?

Interestingly, some vaccines can activate mechanisms that provide relief in diseases other than the ones they were produced for. For example, tests are being designed to see if Mw, a vaccine against leprosy, and MMR, a vaccine against measles, mumps and Rubella can help prevent or ease some of the worst symptoms of COVID-19. While these vaccines will not provide long-term immunity against the SARS-CoV-2 virus, they might work like drugs that make the disease easier to endure.

MYTH 9 Vaccines are dangerous.

FACT Vaccines are tested rigorously (first on animals, and then on increasing batch sizes of human beings) for any adverse effects. Only after they are certified safe for use, are they made available to us. Some vaccines can have undesirable effects like fever, soreness, and muscle ache, but these are short-lived. Very rarely do people develop more serious complications. ABOUT THE Author:

Somdatta Karak leads science communication and public outreach at CSIR-CCMB, Hyderabad. She is also part of the Superheroes against Superbugs initiative that aims to inform on antibiotic resistance in the country. She can be contacted at [email protected]. Illustration & Design: Vidya Kamalesh

A publication by:

Azim Premji University Azim Premji University

Other Magazines of Azim Premji University

Issue 4 ǀ July 2019 Triannual ǀ Bangalore Issue 3 | August 2019 | Half-Yearly | Bengaluru Azim Premji University

RNI No. KARENG/2018/76650 No. RNI Rediscovering School Science RNI No.: KARENG/2018/76619

Page 72 Pedagogy of Dirty Hands

5 Features 22 ClassRoom 77 TechSpace » From Regular Pentagons to the » Circles inscribed in Segments » Exploring Fractals - Icosahedron via the Golden Ratio - I » Radii of Incircle and Ex-circles The GeoGebra Way of a Right-Angled Triangle » The Constants of Mathematics - IV A publication from Azim Premji University » ‘CuRe’ Triplets RATIO

Issue 2 | January 2019 | Half-Yearly | Bangalore

CfÃA ¥ÉæÃAf «±Àé«zÁå®AiÀÄzÀ ®¤ðAUï PÀªïð ¸ÀAaPÉ 5, K¦æ¯ï 2019 MAzÀÄ ¥ÀæPÀluÉ

RNI No. KARENG/2018/76650 No. RNI Rediscovering School Science

Page 8 Metal-organic M¼ÀUÀqÉ: frameworks: zÀÈ¶ÖPÉÆÃ£ÀUÀ¼ÀÄ The new all-rounders in ¸ÀªÀÄ£ÀéAiÀÄPÉÌ CqÉvÀqÉUÀ¼ÀÄ ¸À ªÀiÁ £À ¸ÀªÀÄ£ÀéAiÀÄvÉAiÀÄ DZÀgÀuÉÀUÀ¼ÀÄ chemistry research

¸ÀªÀÄ£ÀéAiÀÄ ²PÀët A publication from Azim Premji University

Issue 2 ǀ January 2019 Issue 2 | January 2019 Triannual ǀ Bangalore Triannual | Bangalore

Azim Premji University

A publication from Azim Premji University RNI No.: KARENG/2018/76591 RNI No.: KARENG/2018/76619

Let the Games Begin!!

Seeing Math in Games and Toys

05 Features 26 ClassRoom 63 TechSpace » Functional Equations - II » Shapes with Sutli: » Mobile Puzzles - Making Sense » The Constants of Mathematics - II The String Game of Variables and Equations » Ramanujan: What might have » Some Down-to-Earth PULLOUT Teaching Learning Materials and Aids been, if only... Trigonometry APPROACHES TO EQUATIONS "...We have such a brief opportunity to pass on to our children our love for this Earth, and to tell our stories. These are the moments when the world is made whole..." — Richard Louv

Catch the next issue of i wonder... to engage with Teaching as if the Earth Matters.

Azim Premji University 080-6614 4900 PES College of Engineering Campus, Electronics City, www.azimpremjiuniversity.edu.in 201697 Hosur Road, Bangalore - 560100 Facebook: /azimpremjiuniversity Instagram: @azimpremjiuniv Twitter: @azimpremjiuniv