Antigenic Analysis of Herpes Simplex Virus by Neutralization Kinetics

Antigenic differences among 15 strains of herpes simplex virus (HSV) were defined by the kinetics of their neutralization by 11 HSV antisera, using rabbit kidney cell monolayers for assaying virus by the plaque technique. A strain of HSV can be uniquely characterized by the rate at which it is neutralized by its homologous antiserum; heterologous strains are neutralized at slower rates. By converting absolute rate constants (K) to normalized rate constants (NK), the rates at which a strain of virus is neutralized by several antisera can be compared. NK values obtained in reciprocal neutralization tests divided these 15 strains into four distinct serogroups and one heterogenous group. Two strains of HSV isolated from the same individual at an interval of two years were antigenically distinguishable. Multiple passages of HSV in rabbit kidney cell cultures had no effect upon its antigenic specificity. These 15 strains cannot be antigenically correlated on the basis of the year of isolation, the clinical manifestation, or the methods used in isolating them.