Active safety monitoring of measles-mumps-rubella vaccine in the National Immunisation Programme of Sri Lanka

Objectives: This study was designed to report incidence and characteristics of selected adverse events following immunisation which have consistent causal association (AEFIc) with Measles-Mumps-Rubella (MMR) vaccination given at the age of one year in the National Immunisation Programme of Sri Lanka. Methods: The data presented here were obtained from a cohort event monitoring study. It was carried out in the Jaffna Regional Directorate of Health Services area from November 2012 to December 2014. A representative sample of 3002 infants who received MMR immunisation were actively followed up for adverse events (AE) using over the phone interviews, self-reporting, and home or hospital visits up to 45 days. All AEs were reviewed by two investigators independently in two step-wise processes to detect the AEFIc. Seven AEFIc were detected using standard case definitions and onset time limit criteria. They were subjected to further analysis to describe the incidence rates and characteristics. Results: Of the 2398 (80%) infants who completed follow up of 45 days, 1321 infants experienced 2621 AEFI. Of them 209 were classified as AEFIc. Incidence of AEFIc was 87/ 1000 immunisation. They were mainly nonserious and resolved completely. There were no fatal or life threatening AEFIs. Incidence per 1000 immunisations; allergic reactions 0.83, injection site reactions 4.58, fever100.4° F or lasting more than  3 days 9.59, macular papular rash 2.92, parotitis 2.92 and generalised convulsions 1.25. Conclusions: The MMR vaccine used in NIP of Sri Lanka had low incidence of AEFIc and were mainly non-serious in nature.