Pushpa Ranjan WijesingheM. R.Nihal AbeysingheSutee YoksanYafu YaoBenli ZhouLei ZhangMansour YaichKathleen M. NeuzilJohn C. VictorMinistry of Health ColomboMahidol UniversityChengdu Institute of Biological ProductsFerney VoltairePATH Seattle2018-11-092018-11-092014-08-20Vaccine. Vol.32, No.37 (2014), 4751-4757187325180264410X2-s2.0-84905229892https://repository.li.mahidol.ac.th/handle/123456789/33230Introduction: To facilitate introduction of live attenuated SA 14-14-2 Japanese encephalitis vaccine (LJEV) into the National Immunization Programme of Sri Lanka, we evaluated the safety and immunogenicity of co-administration of LJEV and measles vaccine at 9 months of age. Serum immune responses were evaluated post-vaccination on days 28, 180, and 365 using JE neutralization test and anti-measles IgG ELISA. Results: 278 infants received one dose of LJEV and measles vaccine. Of these, 257 were eligible for the per-protocol analysis. On Day 0, 14 infants (5.5%) were seropositive for JE, but none were seropositive for measles. At Day 28, seropositivity rates were 90.7% (95% CI, 86.4-93.9%) for JE and 84.8% (95% CI, 79.8-89.0%) for measles. The geometric mean titer for JE neutralizing antibodies was 111 (95% CI, 90-135), and the geometric mean concentration (GMC) for anti-measles IgG was 375. mIU/mL (95% CI, 351-400. mIU/mL). Over the next year, JE neutralizing antibody responses declined only slightly, with seropositivity at 87.4% (95% CI, 82.6-91.2%) at Day 365. In contrast, measles antibody levels continued to increase over time. Seropositivity for anti-measles IgG reached 97.2% (95% CI, 94.4-98.9%) at Day 365, and the GMC rose to 1202. mIU/mL (95% CI, 1077-1341. mIU/mL). Co-administration of LJEV and measles vaccine was also safe. Most adverse reactions were mild, and no serious adverse events were related to study vaccinations. Conclusion: The safety and immunogenicity of LJEV co-administered with measles vaccine in Sri Lankan infants is similar to that seen in other populations, and our results support use of LJEV at 9 months of age. Live SA 14-14-2 vaccine is now prequalified by the WHO for use in infants in Asia, and other countries may wish to introduce LJEV to combat this devastating disease. © 2014 The Authors.Mahidol UniversityBiochemistry, Genetics and Molecular BiologyImmunology and MicrobiologyMedicineVeterinaryArticleSCOPUS10.1016/j.vaccine.2014.06.036