Humoral and cellular immune responses by normal individuals to hepatitis B surface antigen vaccination

The kinetics of the cellular and humoral responses of 30 recipients of hepatitis B vaccine were studied. All individuals exerted an HBsAg blastogenic response sometime throughout the study period but the maximum response was detected on day 28 and 56. The removal of CD8+ cells enhanced significantly the HBsAg response at the times tested, whereas treatment with anti-CD4, anti-CD8, C' and anti-CD4+ C' had no effect. Vaccination also led to the depression of phytohaemagglutinin (PHA) blastogenic response. This response was maximally suppressed 4 to 8 days after immunization at least for the primary and secondary responses and 28 days after the third dose of vaccine. The humoral response to HBsAg was detected only after the second dose of vaccine was given. The results suggest that a CD8+ cell controls the magnitude and intensity of the HBsAg blastogenic response, which may help to explain why several investigators had not been able to detect this response in hyperimmunized individuals. Primary immunization with HBsAg does lead to an expansion of B memory since a secondary response anti-HBsAg was observed.