Avirulent mutants of the CVS strain of rabies virus.

Two avirulent mutants of the CVS strain of rabies virus have been isolated on the basis of their loss of sensitivity to antiglycoprotein neutralizing monoclonal antibodies. With the exception of virulence, both retain general characteristics of the CVS strain of the rabies virus. After inoculation, they induce a strong and rapid immune response in adult mice. In this respect, however, they are quite different from the parental CVS strain. Surviving mice are protected against intramuscular challenge with 10(3.4 LD50 of a field isolate of rabies virus.