Adverse Events Following Immunisation and Global Scenario in Vaccine Pharmacovigilance

Abstract

The safety of vaccines is a high priority for vaccine manufacturers and drug regulatory bodies. Adverse event following immunization (AEFI) is an untoward, temporally associated event following immunization process which does not necessarily have a causal relationship with administration of vaccine. Vaccine pharmacovigilance relates to detection, assessment, understanding, prevention and communication of adverse events following immunization, or of any other vaccine - or immunization- related issues. AEFI aggravate public opposition to immunisation and jeopardize the effectiveness of immunisation campaigns. AEFI are of various types and may be due to programmatic errors, vaccine-induced or potentiated errors. Global vaccine pharmacovigilance systems focus on passive, active or hybrid systems, record linkage and rapid cycle analyses. The global advisory committee on vaccine safety also plays an important advisory role to WHO in vaccine pharmacovigilance. Majority of the population are however exposed to non-functional systems. Thus, a global vaccine safety data network can be useful in solving this problem. WHO AEFI reporting system contains a checklist and causality assessment criteria. It can be made more effective by acting on results of assessment tools. AEFI reporting in India is an elaborate process under the charge of the CDSCO, Ministry of Health and Family Welfare. However, capacity to detect and respond to AEFI needs improvement. A multipronged approach by WHO involving national authorities, multilateral agencies, nongovernmental and professional organizations, academia, healthcare institutions, pharmaceutical industry, lay public and media is the key to ensuring effective vaccine safety monitoring worldwide.