SUMMARY

Mice could be significantly protected against infection with herpes simplex virus (HSV) by i.p. or i.v. injection of killed Corynebacterium parvum 7 days before infection. This protection was seen i inbred strains of mice with a different degree of sensitivity to HSV and after both i.p. and i.v. infection. Resistant mice immuno-suppressed by X-irradiation and showing an increased susceptibility to HSV could also be protected by a previous injection of C. parvum. Elevated levels of interferon were demonstrated in the serum of mice injected with C. parvum 5 to I2 days previously. Four different strains of anaerobic oryneforms were compared and only those which were able to induce a systemic activation of the lymphoreticular system (as reflected by splenomegaly) protected against HSV infection. Protection against HSV-infection could also be demonstrated by using killed Bordetella pertussis. C. parvum also protected against Semliki Forest virus infection in two different strains of mice