Cellular and humoral modifications during response to HBsAg vaccine in healthy subjects

Summary Eighteen healthy adult male subjects, living in a work environment with hepatitis B surface antigen (HBsAg) carriers, were vaccinated against hepatitis B with French vaccine. Immunological monitoring, performed on days 0, 15, 30, 45, 60, 90 and 120, concerned (1) specific humoral and cell-mediated immunity to HBsAg (cell-mediated immunity was explored in only 13 subjects by the leukocyte migration inhibitory test, or LMIT), (2) autologous mixed lymphocyte reaction (AMLR), (3) OKT3-, T4- and T8-positive lymphocytes, (4) the study of phagocytic respiratory activity, and (5) autoantibodies and circulating immune complexes (CIC). Absolute clinical, hepatic and immunological safety, as documented by the absence of clinical side-effects, no change in serum transaminase levels and the lack of appearance of CIC and/or autoantibodies, was observed. Specific seroconversion, absent on the 15th day, reached 89% in subjects by the 90th day, whereas specific cell-mediated conversion seemed to occur earlier (many subjects already showed LMIT positivity by day 15). For monoclonal antibodies and AMLR, an increase in OKT8+ lymphocytes on day 60, seen only among normal responders, was observed with a subsequent reduction in the OKT4/OKT8 ratio and a reduction of the proliferative response in AMLR on the 45th day (except in the only non-responding subject tested). No significant variations in granulocyte respiratory activity were evident. These results are discussed, focusing on the role of cellular immunity during anti-HBsAg vaccination.