Comparative multicentre study of the immunogenicity of different hepatitis B vaccines in healthy volunteers

In a comparative study of the immunogenicity of different hepatitis B vaccines, 339 healthy seronegative adults at three different centres were randomly allocated to receive either three doses of a yeast-derived vaccine at one of three different dose levels (10, 20, or 40 micrograms; SmithKline Biologicals) or one of two commercial plasma-derived vaccines at standard dose levels (5 micrograms, Institut Pasteur Production or 20 micrograms, Merck Sharp & Dohme). The subjects were inoculated intramuscularly in the deltoid region according to a 0, 1, and 6 month schedule. No severe or serious adverse reactions attributed to any of the vaccines were observed. One month after the third vaccine dose, seroconversion rates ranged from 95% to 100% in all groups with only 6 subjects failing to seroconvert. Although there were no statistically significant intra-centre differences in antibody levels, the Tours/Chateauroux groups generally attained higher antibody levels than those from Limoges for the same yeast-derived vaccine dose. This unexplained difference between centres was not found for the plasma-derived vaccines. Older subjects responded less well than younger ones and females attained higher antibody levels than did males. The yeast-derived vaccine is comparable to the two commercially available plasma-derived vaccines in terms of reactogenicity and immunogenicity.