Neutralization of interferon produced early during rabies virus infection in mice.

Inoculation of mice (strain C3H/He) with a purified preparation of fixed rabies virus led to the production of interferon with two different peaks of activity detectable in the plasma: an early peak 24 h after inoculation followed by another peak on the 7th day after infection. The level of splenic 2-5A synthetase was enhanced in parallel with the pattern of interferon activity. Neutralization of the first peak of interferon activity by anti-mouse alpha/beta interferon globulin blocked the induction of splenic 2-5A synthetase and modified the development of disease. Infected mice given anti-interferon globulin had a significantly shorter morbidity period than normally infected mice. These results suggest that interferon produced early after virus inoculation plays a role in the onset of rabies disease.