IMMUNOGENICITY OF AN INACTIVATED HEPATITIS-A VACCINE IN DUTCH UNITED-NATIONS TROOPS

Limited information existed on the immunogenicity of an inactivated he patitis A vaccine as part of art extensive vaccination schedule. Dutch marines bound for duty in Cambodia received inactivated hepatitis A v accine (720 ELISA units of antigen, two intra-gluteal doses at a 2-wee k interval before departure and an intra-deltoid booster vaccination a fter 8 months) simultaneously with several other vaccines, Hepatitis A antibodies were determined in blood-samples drawn before and after th e booster vaccination, using two laboratory rests (modified HAVAB and SBB-ELISA). At 8 months, before the booster vaccination, 52% (modified HAVAB) and 81% (SBB-ELISA) had seroconverted. Risk factors for non-se roconversion were increasing age and a typhoid vaccination. At 11 mont hs 97.6% (modified HAVAB) and 100% (SBB-ELISA) had seroconverted. Non- seroconversion at 8 months was remarkably high. SBB-ELISA was more sen sitive in lower titre ranges. (C) 1997 Elsevier Science Ltd.