Three types of viral sensitivity were observed in various mouse strains upon MHV3 infection: resistance, full susceptibility, and semisusceptibility. In the latter type, seen in several inbred strains including C3H, approximately 50% of the adult injected animals resisted to the acute disease. Most of the surviving mice, however, developed a chronic disease with a wasting syndrome and occurrence of paralysis. The chronic period of the disease was characterized by a persistent viral infection, since MHV3 virus was recovered from brain, liver, spleen, and lymph nodes throughout the evolution in most of the animals. In addition, a correlation was observed between the clinical evolution and the titer of virus tested 4 days after infection.
The research was supported by I.N.S.E.R.M. contract ATP 8-74-29 and by a grant from the Université Paris-Sud.
This work was presented in part at the 57th Annual Meeting of the Federation of American Societies for Experimental Biology, Atlantic City, N. J., April 15–20, 1973.