Poster Presentations

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. Kim^5
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.