title: Immunogenicity and Safety of a Booster Dose of a Live Attenuated Japanese Encephalitis Chimeric Vaccine Given 1 Year After Primary Immunization in Healthy Children in the Republic of Korea.
abstract: BACKGROUND
  This study evaluated the effect of a booster vaccination of a new, live attenuated, Japanese encephalitis chimeric vaccine (JE-CV). Previously this vaccine has been used as a booster 12 months after priming with an inactivated vaccine and at >24 months after priming with the same JE-CV. This study evaluates the immunogenicity and safety of the JE-CV given at 12-24 months after JE-CV priming.
  
  
  METHODS
  Phase III, open-label study in the Republic of Korea in which 119 children previously vaccinated with JE-CV at 12-24 months of age received a JE-CV booster at 12-24 months after primary vaccination. JE neutralizing antibody titers were measured using >50% plaque reduction neutralization test prebooster and 1 month postbooster vaccination. Seroprotection (SP) was defined as ≥10 (1/dil). Safety was assessed for 28 days postvaccination by parental reports. Serious adverse events were monitored for 6 months postvaccination.
  
  
  RESULTS
  Antibody persistence was high prebooster (SP rate 93.5%). There was a strong anamnestic response postbooster vaccination, with an SP rate of 100% and a >50-fold increase in geometric mean titer from the prebooster level. Both antibody persistence and the booster response were independent of whether the booster was given at 12-17 or 18-24 months. The safety profile was good and comparable with the primary vaccination; there were no vaccine-related serious adverse events and no deaths.
  
  
  CONCLUSIONS
  This study confirms the suitability of a JE-CV booster vaccination at 12-24 months after a primary dose of the same vaccine given at 12-24 months of age in children in the Republic of Korea.
authors.affiliation: From the *Yonsei University College of Medicine, Severance Children's Hospital, Seoul, Korea; †National Health Insurance Service Ilsan Hospital, Gyeonggi-do, Korea; ‡KyungHee University Hospital, Seoul, Korea; §Hallym University Dongtan Sacred Heart Hospital, Gyeonggi-do, Korea; ¶Wonju Severance Christian Hospital, Gangwon-do, Korea; ‖Gangnam Severance Hospital, Seoul, Korea; **The Catholic University of Korea Seoul St. Mary's Hospital, Seoul, Korea; ††The Catholic University of Korea St. Vincent's Hospital, Gyeonggi-do, Korea; ‡‡Medical Department, Sanofi Pasteur, Seoul, Korea; §§Global Pharmacovigilance Department and ¶¶Global Medical Affairs, Sanofi Pasteur, Lyon, France; ‖Clinical Department, Sanofi Pasteur, Singapore; and ***Clinical Department, Sanofi Pasteur, Marcy l'Etoile, France.
authors.forename: Dong Soo
authors.initials: DS
authors.lastname: Kim
authors.forename: Gwang Cheon
authors.initials: GC
authors.lastname: Jang
authors.forename: Sung-Ho
authors.initials: SH
authors.lastname: Cha
authors.forename: Soo-Han
authors.initials: SH
authors.lastname: Choi
authors.forename: Hwang Min
authors.initials: HM
authors.lastname: Kim
authors.forename: Ji Hong
authors.initials: JH
authors.lastname: Kim
authors.forename: Jin Han
authors.initials: JH
authors.lastname: Kang
authors.forename: Jong-Hyun
authors.initials: JH
authors.lastname: Kim
authors.forename: Ki Hwan
authors.initials: KH
authors.lastname: Kim
authors.forename: Joon
authors.initials: J
authors.lastname: Bang
authors.forename: Zulaikha
authors.initials: Z
authors.lastname: Naimi
authors.forename: Alain
authors.initials: A
authors.lastname: Bouckenooghe
authors.forename: Valérie
authors.initials: V
authors.lastname: Bosch-Castells
authors.forename: Guy
authors.initials: G
authors.lastname: Houillon
mesh_terms: D057134:Antibodies, Neutralizing / Q000097:blood*; D000914:Antibodies, Viral / Q000097:blood; D002675:Child, Preschool; D064420:Drug-Related Side Effects and Adverse Reactions / Q000453:epidemiology / Q000473:pathology; D004672:Encephalitis, Japanese / Q000517:prevention & control*; D005260:Female; D006801:Humans; D007117:Immunization, Secondary / Q000009:adverse effects*; D007223:Infant; D022321:Japanese Encephalitis Vaccines / Q000008:administration & dosage / Q000009:adverse effects* / Q000276:immunology*; D008297:Male; D056910:Republic of Korea; D016896:Treatment Outcome; D014613:Vaccines, Attenuated / Q000008:administration & dosage / Q000009:adverse effects / Q000276:immunology; D010948:Viral Plaque Assay
chemical_list: D057134:Antibodies, Neutralizing; D000914:Antibodies, Viral; D022321:Japanese Encephalitis Vaccines; D014613:Vaccines, Attenuated