Adverse events following immunizations: Fact and fiction

Abstract

As a public health measure, vaccines have been the most successful strategy in reducing morbidity and mortality internationally. Like all medicines, vaccines can have side effects, or adverse events following immunization (AEFI). As vaccines are predominantly administered to healthy individuals at a population level, there is an added responsibility to monitor AEFI closely. The phrase 'primum non nocere' or 'first do no harm' is ingrained in medical teaching and can be applied to vaccines, including the requirement to undergo vigorous testing in well-conducted scientific experiments before being licensed for use. Due to the inevitable limitations of sample size, common AEFI are those usually..