Pharmacovigilance of Vaccines
BY PROF. SATISH SHARMA DEAN, SCHOOL OF PHARMACY, GLOCAL UNIVERSITY, SAHARANPUR Contents
Introduction
Need for pharmacovigilance of vaccines
Vaccine failure
Adverse events following immunization Introduction
Vaccine is a complex biological preparation that provides active acquired immunity to a particular infectious disease.
Vaccination is the process of administration of antigenic material to stimulate an individual's immune system to develop adaptive immunity to a pathogen. It is one of the most effective ways to prevent diseases
Vaccine pharmacovigilance is defined as “the science and activities relating to the detection, reporting, assessment, understanding and prevention of AEFI or of any other vaccine or immunization-related issues. Need for Pharmacovigilance of Vaccines
To promote the safe use of vaccines among their recipients
Early detection of adverse events
Vaccines are generally given to healthy persons
Most of the vaccines are administered to infants and children
Vaccines are administered globally to a large population
Vaccines are often administered concomitantly with other vaccines
Vaccines are complex biological products Adult vaccination 9 month old immunization Vaccine Failure
A vaccine failure is when disease occurs in a person despite being vaccinated for it Types of vaccine failure
Primary vaccine failure: This is when a person fails to produce antibodies (at detectable levels) or does not produce enough antibodies considered necessary to protect from the disease.
Secondary vaccine failure: This is when a person does produce antibodies in response to vaccination. However the levels wane and decline at a faster rate than normally expected. However, antibodies to almost all vaccines decline over time, even after booster shots, so secondary vaccine failuire in outbreaks of disease amongst the vaccinated is frequent. Cause of vaccine failure
Poor cold chain maintenance
Poor vaccine storage
Inappropriate vaccine transportation
Poor water quality for reconstitution of vaccine
Exposure to UV light (direct sunlight)
Poor vaccine condition
Wrong timing of vaccination
Incorrect vaccination technique Cause of vaccine failure
Improper duration of vaccination
Health status (poor health)
Presence of respiratory diseases
Immunosuppression
Inappropriate choice of vaccine
Poor responsiveness in allergic and obese persons
Aging Awareness Adverse events following immunization
Adverse events following immunization (AEFI) is defined as any untoward medical occurrence which follows immunization and which does not necessarily have a causal relationship with the usage of the vaccine. How do vaccines cause adverse events
1. Vaccine product-related reaction: inherent property of the vaccine formulation 2. Vaccine quality defect-related reaction: deficient quality of the vaccine, diluent and/or delivery equipment from the manufacturer’s side 3. Immunization error-related reaction: due to inappropriate handling or administration of the vaccine, thus preventable 4. Immunization anxiety-related reaction: arising from anxiety about immunization 5. Coincidental event: is caused by something other than the vaccine product, immunization error or immunization anxiety Vaccine product/quality related reaction
Type of vaccine
Manufacturing process
Dose
Adjuvants
Preservatives
Stabilizers
Interaction with other vaccine
Ocular respiratory syndrome from a new influenza vaccine Injection process related events
Injury to surrounding tissues
Syncope (head injury, neurological events)
Bleeding
Contamination of multi-dose vials
Transmission of blood borne pathogens
Inappropriate diluents
Shoulder injury AEFI based on severity
1. Common minor AEFIs – they include local reactions, fever and systemic symptoms
2. Serious AEFIs – those AEFIs which result in hospitalization, death or significant disability
3. Severe AEFIs – reactions which are not minor but do not also result in disability or death and do not require hospitalization Examples of AEs
BCG vaccine: osteitis
Oral polio vaccine: vaccine associated paralytic poliomyelitis
Measles vaccine: febrile seizures, thrombocytopenic purpura, anaphylaxis
Yellow fever vaccine: hypersensitivity reactions
Hepatitis B vaccine: anaphylaxixs
Tetanus toxoid: anaphylaxis AEFI surveillance and monitoring channel AEFI monitoring cycle Objectives of AEFI surveillance Pharmacovigilance of vaccines in India
India is one of the largest manufactures and exporters of vaccines
India runs one of the largest immunization programs (Universal Immunization Program, UIP) in the World
UIP targets 27 million newborns and 30 million pregnant women every year
AEFI (Adverse events following immunization program) surveillance program was initiated by the Government of India in 1986
National and state AEFI committees were set up in 2008
National AEFI Secretariat was established in Health and Family Welfare Department Pharmacovigilance of vaccines in India
AEFI Technical Collaborating Centre was established at Lady Harding Medical College, New Delhi
AEFI Surveillance and Response
Auxiliary Nurse Midwife, Medical Officers, Health Workers, District Health Authority
Monthly Routine Reporting and Immediate serious AEFI
Primary Health Centre, Community Health Centre, District Immunization Centre
AMC or NCC