The influence of different modes of immunization on the experimental genital herpes simplex virus infection of mice.

Previous investigations, which simulated the usual sequence of the human Herpes simplex virus (HSV) infections, had shown that the oral infection of mice with HSV-1 caused only weak protection from genital infection with HSV-2, although the course of infection was attenuated and lethality diminished. This heterologous, heterotopic model was compared with a homologous, heterotopic and a heterologous, homotopic model. The results did not differ very much, although the homologous immunization protected best from lethal outcome, the homotopic immunization best from local infection. Three different preparations of a killed vaccine from purified HSV-1 virion had little effect on the course of the local infection, although protection from lethal outcome was as good as with live virus. In contrast, a crude UV-inactivated vaccine protected nearly completely from local infection. Latent infection in the lumbosacral ganglia was significantly inhibited by immunization with live virus, but only slightly prevented by killed vaccine. The prevalence of latent infection correlated with the extent of vaginal infection. The results show that neither the viral type nor the inoculation site used for immunization with live virus are very critical. Moreover, they allow the conclusion that generalized type-dependent immune factors seem to be engaged in protection against lethal disease; these may be circulating humoral antibodies. On the other hand, locally induced immune factors (probably cellular) are apparently of prime importance for the protection from acute local and latent ganglionic infection.