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(TM) or Havrix(TM), at 0 and 24 weeks. Doses used were 50 or 100 antigen units (U) of Vaqta(TM) and 1440 enzyme linked immunosorbent assay U of Havrix(TM) given as 1 mi 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(TM) than with Vaqta(TM), irrespective of dose given. Systemic tolerance was similar for the 3 regimens. From 4 weeks after the first dose, greater than or equal to 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(TM) 50 U/dose, Vaqta(TM) 100 U/dose and Havrix(TM) 1440 U/dose, respectively. The 2 vaccines had similar immunogenicity but local tolerance was better with Vaqta(TM). (C) 1999 Elsevier Science Ltd. All rights reserved.