Serologic Classification of Herpes Simplex Viruses

Roizman et al. in a recent publication (1) raised a provocative issue concerning the serologic classification of herpes simplex viruses. We agree with these investigators that herpes simplex viruses should be placed in one serologic group, and offer additional arguments in favor of this proposal. Our comments are based on studies that were carried out concerning serologic relationships between intra- and interspecies herpesvirus variants as determined by 50% neutralization endpoints. Employing antisera prepared in rabbits by intravenous (i.v.) immunization, it was noted that the 7S and 19S antibodies fractionated from early (7 day) and late (7 week) immune sera differed in their neutralizing properties against the immunizing or isologous herpesvirus strain (2). These differences were reflected in the ability of these four antibody fractions to neutralize virus alone and to sensitize virus for subsequent neutralization by complement (C) or anti-γ globulin.