Session Title: VACCINE AND PREVENTION
IMMUNOGENECITY AND SAFETY OF INACTIVATED JAPANESE ENCEPHALITIS VACCINE IN KOREAN CHILDREN
Y.J. Hong1, B.Y. Kim1, N.H. Kim2, S.H. Shin3, Y.M. Ahn4, J.Y. Kim5
1Department of Pediatrics, Inha University, Incheon, 2Department of Pediatrics, Inje University, 3Department of Pediatrics, Hallym University, 4Department of Pediatrics, Eulji University, 5Department of Pediatrics, National Medical Center, Seoul, South Korea
Background and aims: The mouse-brain inactivated Nakayama strain Japanese encephalitis vaccine (inactivated JEV) which was introduced in 1971, has not been supported by objective data on its immunogenecity and safety in children < 3 years of age in Korea. Therefore, we need a reliable data by the prospective study on the immunogenecity and the safety of inactivated JEV.
Methods: We measured the neutralizing antibody(NTAb) titers from samples in normal 1-3 year old healthy 80 children during the pre-vaccination period and 4-6 weeks after the 2nd dose for inactivated JEV. The 2nd dose of the inactivated JEV vaccinated 1-2 weeks after 1st dose. Active monitoring was done through phone calls 1-2 weeks after the 1st and 2nd doses of the inactivated JEV. The adverse reactions were recorded on the diary cards by parents, for 4 weeks from the second dose of the inactivated JEV.
Results: The children who received the 2 doses of the inactivated JEV were tested positive for NTAb as 93.8% which was defined as a serum titer greater than 1: 10. The geometric mean of the NTAb was 30.5. The adverse reactions were noted in 52.2%. After the 1st dose, localized reactions were 13.0% and systemic reactions were 13.0%. After the 2nd dose, the localized for 16.3%, and the systemic for 7.6%.
Conclusion: From the current schedule of inactivated JEV, appropriated level of neutralizing Ab was achieved, The adverse reactions were reported higher than previous Korean studies, but most of them were mild.