A secondary objective of this study was to document persistence of immunity up to one year after a single JE-CV vaccination. It has been demonstrated in previous studies [6], [7] and [14] that seroprotection rates after a single JE-CV primary vaccination are well maintained over time. A seroprotection

rate of 84% and GMT of 62 has been reported 1 year after immunization [6], and a seroprotection rate of 80% and GMT of 39 have been reported after 2 years [14]. Our study differs from previous reports in that we assessed immunogenicity 42 days after vaccination, compared with 28 days in previous studies. Our data were nevertheless comparable with previous reports of titers of 281 [6] and 214 [7] 28 days after vaccination with JE-CV. Immune responses remained high for all antigens up to one year after selleck products vaccination irrespective of whether vaccines

were administered separately or concomitantly. There was no marked impact in the persistence of seroprotection for the three MMR antigens due to the order of the vaccinations. Against JE, while a slightly lower seroprotection rate was seen at M12 after co-administration than in the other two groups, the GMTs remain well above the threshold Ceritinib concentration for protection. It is also comparable with data from previous studies assessing a single dose of JE-CV for primary immunization in Asian toddler populations living in endemic areas [6] and [14]. A booster vaccination is recommended after 12 months, and another when children

are 6 years old. Co-administration did not adversely affect the safety or reactogenicity profile compared with separate vaccinations and, consistent with all previous studies of JE-CV, no safety concerns were identified. These data support the possibility of co-administering the JE-CV and MMR vaccines, where needed to facilitate vaccination schedules and potentially to help increase compliance. Idoxuridine JE-CV induces a protective immune response which persists over time irrespective of sequential or concomitant administration with an MMR vaccine. JE-CV was safe at a dose eliciting a protective immune response which persisted up to at least 12 months after vaccination. Co-administration of JE-CV with MMR vaccine can be proposed as part of a routine vaccination program and could be recommended to facilitate immunization of children against these diseases at a single visit. Emmanuel Feroldi, Mark Boaz, Yanee Hutagalung, and Alain Bouckenooghe are employees of Sanofi Pasteur. Li-Min Huang, Tzou-Yien Lin, Cheng-Hsun Chiu, Nan-Chang Chiu, Po-Yen Chen and Shu-Jen Yeh have no conflicts of interest to declare. The study sponsor and manufacturer of the investigational vaccine, Sanofi Pasteur, was involved in the trial design, the management and analysis of data and in the decision to publish.