IgM antibody responses to hepatitis B surface antigen in recipients of hepatitis B virus vaccine

Both total anti-HBs and specific IgM anti-HBs were assayed in sequential serum specimens from five healthy volunteers receiving a primary immunization with the HBV vaccine. Four of the five subjects developed anti-HBs in the six-week period following primary immunization. Anti-HBs was first detectable between days 4 and 21 after initiation of vaccination. Specific IgM anti-HBs was detectable in all four patients who responded to the initial inoculation. This antibody was often present before anti-HBs was detectable by the conventional RIA. However, the titers of IgM anti-HBs were invariably low, and this antibody response was short lived (less than 21 days). The lack of a vigorous and sustained IgM antibody response to HBsAg has also been noted after infection with HBV [1, 2]. This observation is in marked contrast to the magnitude of IgM response to hepatitis B core antigen, which is detectable in high titers during acute HBV infection and persists for months to years after the disease has resolved [2, 3]. The significance of the weak IgM antibody response to HBsAg during both immunization with HBV vaccine and HBV infection is not known but may be related to the relatively low immunogenicity of HBsAg. This weak IgM antibody response may play a role in the propensity of persons with HBV infection to develop the chronic HBsAg carrier state.