Administration of hepatitis A vaccine at 6 and 12 months of age concomitantly with hexavalent (DTaP-IPV-PRP approximately T-HBs) combination vaccine.

Author(s): Stojanov S, Liese JG, Belohradsky BH, Vandermeulen C, Hoppenbrouwers K, Van der Wielen M, Van Damme P, Georges B, Dupuy M, Scemama M, Watson M, Fiquet A, Stek JE, Golm GT, Schodel FP, Kuter BJ, the HEXAVAC((R))/VAQTA((R)) Study Group

Affiliation(s): University Children's Hospital, Ludwig-Maximilians-University, Munich, Germany.

Publication date & source: 2007-10-23, Vaccine., 25(43):7549-7558. Epub 2007 Sep 4.

BACKGROUND: Administration of two doses of hepatitis A (HA) vaccine to children >/=2 years of age has been shown to be protective. The present study assessed whether HA vaccine can be administered as early as 6 months of age and whether it can be administered concomitantly with a hexavalent (HV) vaccine at this age. METHODS: In an open label, randomized, parallel group study, the liquid HV vaccine (HEXAVAC((R))) (diphtheria, tetanus, 2-component acellular pertussis, inactivated poliomyelitis vaccine, Haemophilus influenzae type b conjugated to tetanus protein and hepatitis B) was administered at 2, 4, 6, and 12 months of age to all children. HA vaccine (VAQTA((R))) was given at 7 and 13 months in the separate administration group (Group 1) and at 6 and 12 months in the concomitant administration group (Group 2). Serum samples were obtained at 2, 7, 12, and 14 months in Group 1 and at 2, 7, 12, and 13 months in Group 2. The primary immunogenicity outcomes were the seroconversion rates for HA 1 month after the second dose of HA vaccine in initially seronegative subjects, and the seroconversion rates for each HV antigen 1 month after the third dose of the HV vaccine (both at 7 months of age). RESULTS: HA seropositivity rates 1 month after the second dose were 100% in both groups, regardless of initial serostatus. The responses to each HV antigen 1 month after the third dose were similar in both groups. The vaccines were generally well tolerated in both groups regardless of vaccine(s) administered. CONCLUSIONS: A schedule of two doses of HA vaccine, 6 months apart beginning at 6 months of age is highly immunogenic and well tolerated when administered alone or concomitantly with HV vaccine at 6 and 12 months of age.