Protection against herpes simplex virus infection in mice by Corynebacterium parvum

Corynebacterium parvum administered in mice prior to herpes simplex virus (HSV) infection significantly protected them against lethal encephalitis. This was seen both with a mouse strain highly susceptible to HSV and with one relatively resistant to HSV. Mice immunosuppressed by cyclophosphamide and showing an increased mortality after HSV infection were also protected by C. parvum pretreatment. However, C. parvum given simultaneously with or after HSV infection did not exert a therapeutic effect.