ASSESSING THE SAFETY PROFILE OF PEDIATRIC VACCINES: PROSPECTIVE MONITORING OF ADVERSE EVENTS IN CHILDREN UNDER TWELVE YEARS

Abstract

Background : Vaccination remains a vital global public health intervention, yet maintaining public trust requires rigorous monitoring of Adverse Events Following Immunization (AEFIs). While passive safety surveillance often suffers from under-reporting, systematic prospective monitoring provides accurate, active capture of both solicited (anticipated reactogenicity) and unsolicited (unexpected occurrences) events. Differentiating true vaccine reactions from coincidental childhood illnesses in developing immune systems requires standard causality frameworks like the WHO-UMC and Naranjo scales. This study evaluates the frequency, nature, and severity of these adverse events across distinct paediatric age cohorts to establish a precise, evidence-based safety profile
Objective: To identify, monitor, and assess both solicited and unsolicited adverse events following immunization in children under twelve.

Methods: In this one-year, prospective observational study, 760 children under twelve who experienced vaccination-related problems at a tertiary teaching hospital were enrolled and divided into three age groups. Data on demographics, vaccine details, adverse events, severity, and causality were collected and analyzed using Naranjo’s scale and WHO-UMC criteria. Statistical significance was set at p<0.05.

Results: 210 solicited adverse events were documented in 174 patients; unsolicited adverse events occurred at varying rates across age groups. Group 3 (>5 years) had more severe adverse events (31.57%) compared to Groups 1 and 2 (p=0.003). Local adverse effects were more common in infants and toddlers (p=0.001). Most adverse events were mild and self-resolving.

Conclusion: Most adverse reactions following vaccination in children under twelve are mild and transient, with age-specific patterns observed.