The course of lymphocytic choriomeningitis virus infection in germfree mice treated with Bordetella pertussis vaccine.

: A single injection of Bordetella pertussis vaccine, applied intraperitoneally one day before intracerebral lymphocytic choriomeningitis virus infection depressed the immune response both in conventional and germfree adult mice, but the rate of the immunosuppressive effect differed. In adult mice with a normal immune system the vaccine only delayed the manifestation of fatal lymphocytic choriomeningitis, while it prevented its development in germfree mice with an underdeveloped lymphoid system, i.e. it inhibited the cellular immune response to the virus infection.