Combined two-dose hepatitis A and B vaccine (AmBirix)

One month after the last dose (i.e. at month 7), geometric mean titres (GMTs) of antibodies directed against hepatitis A virus (anti-HAV) were generally greater in participants (aged 12-15 years) receiving combined two-dose (0 and 6 months) hepatitis A and B vaccine (AmBirix) compared with the three-dose (containing one half the dose of the two active components per dose, given at 0, 1 and 6 months; Twinrix Paediatric) schedule. Moreover, at month 7 all patients had seroconverted to anti-HAV. GMTs of antibodies directed against hepatitis B surface antigen greatly exceeded the threshold for seroprotection (>/=10 mIU/mL) 1 month after the last dose of vaccine. Seroprotection rates against hepatitis B virus (HBV) were similar 1 month after completion of either a two- (97.9%) or three-dose (100%) vaccination schedule. At 24 months' follow-up, all patients tested remained positive for anti-HAV, and 93.3% and 96.2% of those treated with the two- and three-dose schedules, respectively, remained above the threshold for seroprotection against HBV. Administering the second dose in the two-dose series at 12 months rather than at 6 months did not compromise the immune response to the combined vaccine in adolescents aged 12-15 years in a randomised, multicentre trial. Local adverse events reported in the 4 days following administration of combined two-dose hepatitis A and B vaccine include pain or soreness, redness and swelling; systemic symptoms included headache, fatigue, gastrointestinal events and fever.