PROTECTIVE PROPERTIES IN MICE OF TONATE VIRUS AND 2 STRAINS OF CABASSOU VIRUS AGAINST NEUROVIRULENT EVERGLADES VENEZUELAN ENCEPHALITIS-VIRUS

  • 1 January 1976
    • journal article
    • research article
    • Vol. B127  (3) , 429-437
Abstract
Venezuelan encephalitis virus is a constant menace to man and to animals, particularly horses. Two as yet unreported strains were isolated in French Guyana: CaAn410d (Tonate) and CaAr508 (Cabassou). They are not neurovirulent after peripheral inoculation into adult mice and guinea pigs. Cabassou is not pathogenic for adult mice after intracerebral inoculation. A 3rd strain, CaAr19007, is antigenically identical by complement-fixation with Cabassou, but appears to cross react with other strains. Tonate, when injected i.p. or s.c., protects adult mice against intracerebral or i.p. challenge with Everglades virus. The CaAr19007 isolate causes total protection against Everglades virus if injected i.p., but only partial protection by the s.c. route. Cabassou, if injected i.p., will protect against intracerebral challenge with Everglades. Tonate and CaAr19007 thus appear to be naturally occurring attenuated variants of the Venezuelan encephalitis virus complex, which can protect mice against intracerebral infection with neurovirulent strains.