Relative Concentrations in Human Sera of Antibodies to Cross-Reacting and Specific Antigens of Herpes Simplex Virus Types 1 and 2

The relative concentrations of antibodies to the cross-reacting and type-specific antigens of herpes simplex virus types 1 and 2 were examined in sera from patients who had been infected by type 1 virus only, by type 2 virus only or by both viruses. Complement-dependent lysis of 51Cr-labeled cells was used to measure antibodies to the surface antigens of cells infected by the viruses. Approximately 80% of the antibody activity was attributable to cross-reacting antigens and 20% to type-specific antigens in sera from patients infected with either type 1 or type 2 virus. Among patients infected with type 1 virus and then type 2 virus, approximately 90% of the antibody activity was to the cross-reacting antigens, 5 to 10% to type 1-specific antigens and little or no antibody to type 2-specific antigens. The observations suggest that infection by type 2 virus in patients with a prior type 1 infection results in an antibody response to the cross-reacting antigens with little or no response to the type-specific antigens.