Unusual serologic response to two patients to an early antigen of herpes simplex virus type 2.

Two patients infected with herpes simplex virus type 2 (HSV-2) who were free of recurrences over a 13-14-month period had an unusually high titer (greater than 1:48) of complement-fixing antibody to the early antigen (AG-4) of HSV-2. Their response was also unusual in that it was an IgG complement-fixing antibody rather than IgM, which normally is found in patients with HSV-2 infection. The antibody was also present 13-14 months after the episode of HSV-2 disease, whereas in other patients, the response had declined by six months.