Adverse events following immunisation with SA 14-14-2 Japanese encephalitis vaccine in children of Kolar in Karnataka.

Around 30 million children of 1 to 15 years have received the live attenuated SA 14-14-2 Japanese encephalitis (JE) vaccine in the campaign against JE in India from 2006 to 2007. This study aims to assess the short-term adverse events following JE vaccination as there is limited data on it in Indian children. A longitudinal study of children vaccinated in the campaign against JE in Kolar, in 2007 was undertaken. In July to August 2007, following the JE vaccination campaign in Kolar, 1640 children of 10 to 15 years were followed for four weeks. Events such as fever, pain at the injection site, cough, headache and nausea or vomiting were recorded. Surveillance was maintained on the referral hospitals for hospitalisation due to encephalitis and anaphylaxis following vaccination. The incidence of adverse events is summarised as frequencies and percentages with 95% confidence interval (CI). The analysis was performed using statistical package for social sciences (SPSS) 15.0 for Windows. The incidence of minor adverse events was 11.3% (95% CI 9.8-12.9%) for fever, 17% (15.2-18.8%) for pain at the injection site, 12.6% (11-14.2%) for cough, 2.6% (1.8-3.3%) for headache and 1.1% (0.6-1.6%) for nausea and/or vomiting. Severe adverse events were not observed. Mild adverse events following immunisation are common with SA14-14-2 JE vaccine. Hence the health personnel involved in JE control campaign should be aware of these adverse events.