A host range difference between herpes simplex virus types 1 and 2.

The infectivities of several strains of herpes simplex virus type 1 and type 2 were measured by plating on established human and Chinese hamster cell lines. Whereas all the type 1 strains reproducibly showed a 10(4)-fold lower titre on the Chinese hamster cells, the type 2 strains showed only a 10- to 100-fold lower titre. This host range difference has been used in the analysis of recombinants between type 1 and type 2 viruses.