AAAS Research Volume 2020, Article ID 6925296, 35 pages https://doi.org/10.34133/2020/6925296 Review Article Combating the Coronavirus Pandemic: Early Detection, Medical Treatment, and a Concerted Effort by the Global Community Zichao Luo,1 Melgious Jin Yan Ang,1,2 Siew Yin Chan,3 Zhigao Yi,1 Yi Yiing Goh,1,2 Shuangqian Yan,1 Jun Tao,4 Kai Liu,5 Xiaosong Li,6 Hongjie Zhang ,5,7 Wei Huang ,3,8 and Xiaogang Liu 1,9,10 1Department of Chemistry, National University of Singapore, Singapore 117543, Singapore 2NUS Graduate School for Integrative Sciences and Engineering, Singapore 117456, Singapore 3Frontiers Science Center for Flexible Electronics & Shaanxi Institute of Flexible Electronics, Northwestern Polytechnical University, Xi’an 710072, China 4Sports Medical Centre, The Second Affiliated Hospital of Nanchang University, Nanchang 330000, China 5State Key Laboratory of Rare Earth Resource Utilization, Chang Chun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun 130022, China 6Department of Oncology, The Fourth Medical Center of Chinese People’s Liberation Army General Hospital, Beijing 100048, China 7Department of Chemistry, Tsinghua University, Beijing 100084, China 8Key Laboratory of Flexible Electronics & Institute of Advanced Materials, Nanjing Tech University, Nanjing 211816, China 9The N.1 Institute for Health, National University of Singapore, Singapore 10Joint School of National University of Singapore and Tianjin University, International Campus of Tianjin University, Fuzhou 350807, China Correspondence should be addressed to Hongjie Zhang; [email protected], Wei Huang; [email protected], and Xiaogang Liu; [email protected] Received 19 April 2020; Accepted 20 April 2020; Published 16 June 2020 Copyright © 2020 Zichao Luo et al. Exclusive Licensee Science and Technology Review Publishing House. Distributed under a Creative Commons Attribution License (CC BY 4.0). The World Health Organization (WHO) has declared the outbreak of 2019 novel coronavirus, known as 2019-nCoV, a pandemic, as the coronavirus has now infected over 2.6 million people globally and caused more than 185,000 fatalities as of April 23, 2020. Coronavirus disease 2019 (COVID-19) causes a respiratory illness with symptoms such as dry cough, fever, sudden loss of smell, and, in more severe cases, difficulty breathing. To date, there is no specific vaccine or treatment proven effective against this viral disease. Early and accurate diagnosis of COVID-19 is thus critical to curbing its spread and improving health outcomes. Reverse transcription-polymerase chain reaction (RT-PCR) is commonly used to detect the presence of COVID-19. Other techniques, such as recombinase polymerase amplification (RPA), loop- mediated isothermal amplification (LAMP), clustered regularly interspaced short palindromic repeats (CRISPR), and microfluidics, have allowed better disease diagnosis. Here, as part of the effort to expand screening capacity, we review advances and challenges in the rapid detection of COVID-19 by targeting nucleic acids, antigens, or antibodies. We also summarize potential treatments and vaccines against COVID-19 and discuss ongoing clinical trials of interventions to reduce viral progression. 1. Introduction 213 countries and territories [1]. On January 30, 2020, WHO declared the COVID-19 outbreak as the sixth pub- The recent global outbreak of COVID-19 has led to a lic health emergency of international concern, following public health emergency. As of April 23, 2020, over 2.6 H1N1 (2009), Polio (2014), Ebola in West Africa million confirmed cases were reported to WHO from (2014), Zika (2016), and Ebola (2019) [2]. The rapid 2 Research global expansion and rising fatalities have raised grave affinity to ACE2 than the S protein of SARS-CoV, enabling concerns on the viral spread across the globe. With the 2019-nCoV to invade host cells more effectively [16, 17]. rapid increase in the number of confirmed cases, WHO Recently, a transmembrane glycoprotein, CD147, also classified the global COVID-19 outbreak as a pandemic known as Basigin or EMMPRIN, has been confirmed as on March 11, 2020 [3]. COVID-19 can spread from another receptor for binding of the 2019-nCoV S protein, person-to-person and animal, and transmission of infec- thereby mediating viral invasion [18]. tion may occur with exposure to symptomatic patients The E protein is an integral membrane protein that regu- or asymptomatic individuals. lates viral life cycles, including pathogenesis, envelope forma- – Coronaviruses (CoVs) (corona: crown-like shape) are tion, assembly, and budding [19 21]. Among the four enveloped, single-stranded RNA viruses that belong to structural proteins, protein E appears to have the highest fi the order Nidovirales in the subfamily Coronaviridae. antigenicity and the most signi cant potential as an immu- CoVs are divided into four genera: alpha (α), beta (β), nogenic target, highlighting the possibility of developing gamma (γ), and delta (δ) (Figure 1(a)) [4]. Alpha- and protein E-derived peptides as a 2019-nCoV vaccine [22]. Sys- beta-CoVs infect mammals, while gamma- and delta- temic studies of proteins S and E have inspired scientists to CoVs primarily infect birds [5]. Before December 2019, take creative approaches to design anti-COVID-19 drugs. six types of CoVs had infected humans, including two α- Although some COVID-19 patients show no symptoms, CoVs (HCoV-229E and HCoV-NL63) and four β-CoVs most patients have some common symptoms such as fever, (HCoV-OC43, HCoV-HKU1, SARS-CoV, and MERS- cough, fatigue, sputum production, shortness of breath, sore CoV). The first two β-CoVs (HCoV-OC43 and HCoV- throat, and headache. In some severe cases, infections can HKU1) mainly cause self-limiting upper respiratory infec- cause pneumonia, severe acute respiratory syndrome, kidney tions, while the other two β-CoVs (SARS-CoV and MERS- failure, and death. According to the WHO-China joint report CoV) are mostly associated with severe respiratory illness [23], on average, people infected with 2019-nCoV develop [6, 7]. Full-genome sequence analysis of 2019-nCoV con- mild respiratory symptoms and fever, 5-6 days after infection firms that it is a β-CoV, distinct from SARS-CoV and (mean incubation period, 5-6 days; range, 1-14 days). People MERS-CoV [8]. Investigations reveal that 2019-nCoV over 60 years of age and those with hypertension, diabetes, or shares ~80% sequence identity with SARS-CoV while cardiovascular diseases are at high risk for severe illness maintaining ~89% nucleotide identity to the SARS-like and death. In comparison, children under 19 years appear CoVs (ZC45 and ZXC21) from bats [9]. A recent report to be infected minimally by 2019-nCoV (around 2.4% of suggests that a bat CoV (RatG13) is 96% identical to all reported cases). Based on the Chinese Center for 2019-nCoV [10]. Disease Control and Prevention (China CDC) report (from 72,314 patient records, dated 11 February 2020), A typical CoV genome is a single-stranded, positive- fi ~ ′ ′ among the con rmed cases, 86.6% of patients are 30-79 sense RNA (+ssRNA) ( 30 kb) enclosed by a 5 -cap and 3 years of age, 80.9% of patients have mild-to-moderate -poly-A tail [11]. The genome size of 2019-nCoV is 29,891 disease, 13.8% have a severe illness, and 6.1% are critically nucleotides, encoding 9860 amino acids, with a G+C content ill [24]. Notably, the mortality rate of children under 19 of 38% [12]. The 2019-nCoV genome contains two flanking ′ ′ years is 0.2%, while people aged over 80 years have the untranslated regions (UTRs) on 5 - and 3 -terminals, one highest mortality rate of 14.8%. single long open reading frame 1ab (ORF1ab) encoding a Currently, there are no effective antiviral drugs or specific fi polyprotein and at least ve other ORFs encoding structural vaccines against COVID-19. Thus, there is an urgent need for fi proteins, and eight accessory proteins (Figure 1(c)). The rst rapid detection to prevent further spread, to reduce the inten- ORF (ORF1a/b) is about two-thirds of the whole-genome sity of the pandemic, and to slow the increase in cases. length and encodes the 16 nonstructural proteins (nsp1- Recently, several new technologies, including LAMP-LFA, 16). The other one-third of the genome contains four ORFs RPA-LFA, RPA-CRISPR, and other nanomaterial-based encoding the spike (S), membrane (M), envelope (E), and IgG/IgM kits, have been adopted for 2019-nCoV detection. nucleocapsid (N) proteins, whereas other ORFs encode A significant number of drug candidates, including chemical accessory proteins (Figure 1(b) and (c)). Most of the non- drugs, biological drugs, nutritional interventions, and tradi- structural proteins are essential for 2019-nCoV replication, tional Chinese medicine (TCM), have been proposed for while structural proteins are responsible for virion assembly clinical trials after the 2019-nCoV outbreak. In this review, and viral infection [12, 13]. The M and E proteins are we concentrate on the most significant developments in required in viral assembly, while the N protein involves 2019-nCoV detection and provide an overview of medical RNA genome assembly. treatments and vaccines currently in development to combat The S protein, a surface-located trimeric glycoprotein of and contain the disease. CoVs, is the primary determinant of CoV tropism, as it binds to the membrane receptor on host cells, mediating 2. 2019-nCoV Detection viral and cellular membrane fusion [14]. The S protein of 2019-nCoV reportedly binds to angiotensin-converting According to the Diagnosis and