Concomitant administration of live attenuated Japanese encephalitis chimeric virus vaccine (JE-CV) and measles, mumps, rubella (MMR) vaccine: Randomized study in toddlers in Taiwan

Abstract Background Japanese encephalitis (JE) is the most important cause of viral encephalitis in Asia. Methods In this randomized, open-label, multicenter trial in 550 children aged 12 to 18 months in Taiwan, children received one dose of JE-CV and one dose of MMR vaccine. Vaccines were either administered separately 6 weeks apart (Groups ‘JE-CV’ and ‘MMR’, named after which vaccine was given first), or concomitantly (Group ‘Co-Ad’). JE neutralizing antibody titers were assessed using PRNT 50 . MMR antibody levels were determined by ELISA. Results All groups had low seroprotection/seropositivity rates ( Conclusions JE-CV is safe and induces a strong protective immune response which persists over 1 year when co-administered with MMR vaccine.