title: Safety and immunogenicity of live-attenuated Japanese encephalitis SA 14-14-2 vaccine co-administered with measles vaccine in 9-month-old infants in Sri Lanka.
abstract: BACKGROUND
  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 mI U/mL (95% CI, 351-400 mI U/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 mI U/mL (95% CI, 1077-1341 mI U/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.
  
  
  CONCLUSIONS
  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.
authors.affiliation: Epidemiological Unit, Ministry Of Healthcare and Nutrition, Colombo, Sri Lanka.
authors.forename: Pushpa Ranjan
authors.initials: PR
authors.lastname: Wijesinghe
authors.affiliation: Epidemiological Unit, Ministry Of Healthcare and Nutrition, Colombo, Sri Lanka.
authors.forename: M R Nihal
authors.initials: MR
authors.lastname: Abeysinghe
authors.affiliation: Mahidol University, Bangkok, Thailand.
authors.forename: Sutee
authors.initials: S
authors.lastname: Yoksan
authors.affiliation: Chengdu Institute of Biological Products, Chengdu, China.
authors.forename: Yafu
authors.initials: Y
authors.lastname: Yao
authors.affiliation: Chengdu Institute of Biological Products, Chengdu, China.
authors.forename: Benli
authors.initials: B
authors.lastname: Zhou
authors.affiliation: Chengdu Institute of Biological Products, Chengdu, China.
authors.forename: Lei
authors.initials: L
authors.lastname: Zhang
authors.affiliation: PATH, Ferney Voltaire, France.
authors.forename: Mansour
authors.initials: M
authors.lastname: Yaich
authors.affiliation: PATH, Seattle, WA, USA.
authors.forename: Kathleen M
authors.initials: KM
authors.lastname: Neuzil
authors.affiliation: PATH, Seattle, WA, USA. Electronic address: cvictor@path.org.
authors.forename: John C
authors.initials: JC
authors.lastname: Victor
mesh_terms: D057134:Antibodies, Neutralizing / Q000097:blood; D000914:Antibodies, Viral / Q000097:blood; D004672:Encephalitis, Japanese / Q000517:prevention & control*; D005260:Female; D006801:Humans; D007115:Immunization Schedule; D007074:Immunoglobulin G / Q000097:blood; D007223:Infant; D022321:Japanese Encephalitis Vaccines / Q000008:administration & dosage*; D008297:Male; D008457:Measles / Q000517:prevention & control; D008458:Measles Vaccine / Q000008:administration & dosage*; D013188:Sri Lanka; D014613:Vaccines, Attenuated / Q000008:administration & dosage
chemical_list: D057134:Antibodies, Neutralizing; D000914:Antibodies, Viral; D007074:Immunoglobulin G; D022321:Japanese Encephalitis Vaccines; D008458:Measles Vaccine; D014613:Vaccines, Attenuated
keywords: Clinical trial; Humoral immune response; Japanese encephalitis vaccines; Measles vaccine; Safety