title: Immunizing children aged 9 to 15 months with live attenuated SA14-14-2 Japanese encephalitis vaccine in Thailand.
abstract: The authors aimed to evaluate the safety and immunogenicity of a live attenuated SA14-14-2 Japanese Encephalitis (JE) vaccine in healthy Thai infants. One hundred and fifty subjects aged 9-15 months were vaccinated with one dose of this vaccine. Regarding the vaccine safety, during the 28-day post-vaccination follow-up, no vaccine-related serious adverse events were reported. In terms of immunogenicity, the sero-conversion rate of a single dose vaccination was 95% (95% CI, 90.0-97.6%) within 90 days after vaccination and the geometric mean titer (GMT) was 66.1. Eight subjects with JE seronegative on days 28-35 post-vaccination became sero-positive on day 90. Seven subjects who remained sero-negative during days 28-35 and day 90 post-vaccination were successfully sero-converted after receiving a second dose 3 months later. Thus, two doses of this JE vaccine resulted in a 100% (95% CI, 97.3-100%) sero-conversion rate with the GMT of 260.8. Eight children with GMTs lower than protective level after a single vaccination demonstrated a booster response with GMT of 1237 after the second dose of JE vaccination. In conclusion, the live attenuated SA14-14-2 vaccine was safe, well tolerated and highly immunogenic with 95% and 100% sero-conversion rate after one and two doses, respectively. Nevertheless, its long-term immune response and possible influences from natural dengue infection requires further evaluation.
authors: Queen Sirikit National Institute of Child Health, College of Medicine, Rangsit University, Bangkok, Thailand.
authors: Tawee
authors: T
authors: Chotpitayasunondh
authors: Young Mo
authors: YM
authors: Sohn
authors: Sutee
authors: S
authors: Yoksan
authors: J
authors: J
authors: Min
authors: Heechoul
authors: H
authors: Ohrr
mesh_terms: D000914:Antibodies, Viral / Q000097:blood; D004305:Dose-Response Relationship, Drug; D004664:Encephalitis Virus, Japanese / Q000276:immunology*; D004672:Encephalitis, Japanese / Q000517:prevention & control*; D005260:Female; D005500:Follow-Up Studies; D006462:Hemolytic Plaque Technique; D006801:Humans; D007114:Immunization; D007223:Infant; D022321:Japanese Encephalitis Vaccines / Q000008:administration & dosage / Q000276:immunology*; D008297:Male; D009500:Neutralization Tests; D013785:Thailand; D014611:Vaccination; D014613:Vaccines, Attenuated / Q000008:administration & dosage* / Q000276:immunology
chemical_list: D000914:Antibodies, Viral; D022321:Japanese Encephalitis Vaccines; D014613:Vaccines, Attenuated