Herpes simplex virus microneutralization: a simplification of the test.

The herpes simplex virus (HSV) microneutralization test has been simplified; its use has been demonstrated for the identification of HSV isolates as type 1 (HSV-1) or type 2 (HSV-2) and for the measurement of antibodies to HSV-1 and HSV-2. In this test, the relation between the neutralization titer and virus input is linear, and thus test results can be expressed as corrected neutralization titers, rather than as the more complex neutralizing potency values previously proposed. By means of this test, 45 of 46 clinical isolates of HSV were unequivocally identified as either HSV-1 or HSV-2. Evaluation of neutralizing antibody to HSV infection was more difficult because some neutralizing antibody to the heterotypic HSV is produced after primary infection with HSV-1 or HSV-2, because patients previously infected with one HSV type may show a variety of serological responses to subsequent heterotypic infection, and because human sera obtained early after primary HSV infection may not yet exhibit a type-specific response.