Antigenic variation in rabies and rabies-related viruses. Cross-protection i dependent of glycoprotein-mediated virus-neutralizing antibody

Immunization experiments with vaccines prepared from the PM and ERA strains of ra-bies virus demonstrated that in mice, only ERA vaccine primes for an anamnestic re-sponse to the rabies-related strain Duvenhage (DUV6); in rabbits, both ERA and PM vaccines induced immunologic memory to DUV6 virus, In mice, ERA vaccine, but not an equal concentration of PM vaccine, conferred protection against a lethal challenge infection with DUV6 virus. This result indicated that the protective activity correlated with the vaccine's ability to induce immunologic memory. A vaccine prepared from a sequentially selected, neutralization-resistant, multiple-variant virus conferred protection against challenge with the parental strain, a result indicating that antigenic variation of the glycoprotein may not be the sole factor in determining the relative efficacy of rabies prophylaxis. We found no correlation between titers of neutralizing antibody and mortal-ity rates in mice immunized with purified glycoprotein from these viruses. Use of monoclonal antibodies (MAbs) to analyze a wide variety of fixed and street rabies viruses has revealed considerable antigenic variability amon