A study of adverse vaccine events among pediatric age group in a tertiary medical college hospital

Background: Vaccines are pivotal health products that are used and administered prophylactically to a large number of healthy individuals. A significant proportion of vaccines are administered to the pediatric age group, particularly to the neonates and infants as part of the national immunization programmes. As with any drug, untoward reaction can occur with the administration of vaccines. Most of the clinical trials with the vaccines are conducted and validated in a relatively small sample size. Active monitoring as part of the Pharmacovigilance programme is imperative to identify rare or deferred adverse vaccine events (AVE). Methods: A prospective, single center, observational, naturalistic study on report forms in pediatric age group, who may develop AVE in Sapthagiri Institute of Medical Sciences and Research Center, Bengaluru, was conducted during the study time widow, from February 20, 2014, to April 20th, 2014. Children under 5 years of age were included in the study. All children more than 5 years of age were excluded from the study. The causality assessment were attempted to be recorded as per the Naranjo score, which is used to quantitatively evaluate the association between AVE and vaccines. Results: 19.04% of children aged 1-5 years of age documented with adverse event following immunization (AEFI) (p=0.036). It was found that either a naive or the fully immunized children suffered from the AEFI most of which was trivial. Fever was the most common AEFI reported followed by an excess cry. The incidence of fever reported was substantially high following the DPT vaccine. Conclusions: All the AEFI received through the telephonic calls were documented. There was no mortality or a major adverse event reported. Maximum AEFI were documented in the neonates and the children 1-5 years of age which was statistically significant. In addition, the study provides a scope for further research with reference to the inter-age group variability. The immune mechanism behind such a difference also needs to be explored.