Comparative immunogenicity and tolerance of Vaqta and Havrix

In an open-label, randomised trial, 520 adults of both sexes aged 18-30 years were allocated to receive one of two inactivated hepatitis A vaccines; Vaqta or Havrix, at 0 and 24 weeks. Doses used were 50 or 100 antigen units (U) of Vaqta and 1440 enzyme linked immunosorbent assay U of Havrix given as 1 ml intramuscular injections. For each trial group safety data were available for all subjects and full serological data for more than 80% of randomised volunteers. Local side effects which were mild in most cases were significantly (p < 0.0001) more common with Havrix than with Vaqta, irrespective of dose given. Systemic tolerance was similar for the 3 regimens. From 4 weeks after the first dose, > or =94% of the subjects had seroconverted. The mean antibody titres 4 weeks after the second vaccine dose were 2978, 4346 and 1589 mIU/ml in subjects who were randomised to Vaqta 50 U/dose, Vaqta 100 U/dose and Havrix 1440 U/dose, respectively. The 2 vaccines had similar immunogenicity but local tolerance was better with Vaqta.