Studies on the neutralizing antibody to herpes simplex virus. I. Effect of heterotypic antigenic stimulus on the type specificity of neutralizing antibody in rabbits.

Effect of heterotypic antigenic stimulus on the antibody response in rabbits previously exposed to only one type of virus was investigated. The complement requiring neutralizing antibody (CRN) was found in the IgM fraction as well as the IgG, but the conventional neutralizing antibody (N) was detected only in the fraction containing IgG. The CRN antibody found in the IgM fraction was most predominantly modified by the inoculation of heterotypic virus, and resulted in a relative increase of CRN antibody titres against the heterotypic virus, whereas antibodies in the IgG fraction, either CRN or N, were slightly affected by the heterotypic stimulus. When the heterotypic virus was given 9 months after the initial inoculation of homotypic virus, the antibody response in teh IgM fraction formed the same pattern as seen in the primary response against the type of virus inoculated as the booster. These findings should pave the way for making accurate serological assessments, including the type of virus in present infections, irrespective of involvement of a superinfection with the heterotypic virus.