ABSTRACT
Administration to rodents (Syrian hamsters, mice, guinea pigs, rabbits) of minimal doses of attenuated strain 15 VEE (up to 20 ImD50) provided protection against respiratory challenge with a highly virulent strain of Venezuelan equine encephalomyelitis virus. The protection is observed in a wide range of doses (up to LD50 hundreds and even thousands).
Subject(s)
Encephalitis Virus, Venezuelan Equine/immunology , Encephalomyelitis, Venezuelan Equine/prevention & control , Respiratory Tract Infections/prevention & control , Rodent Diseases/prevention & control , Viral Vaccines/immunology , Animals , Cricetinae , Drug Evaluation, Preclinical , Encephalitis Virus, Venezuelan Equine/pathogenicity , Encephalomyelitis, Venezuelan Equine/etiology , Guinea Pigs , Immunization , Mesocricetus , Mice , Rabbits , Respiratory Tract Infections/etiology , Rodent Diseases/etiology , Serial Passage , Vaccines, Attenuated/administration & dosage , Vaccines, Attenuated/immunology , Viral Vaccines/administration & dosage , VirulenceABSTRACT
Immunization of Papio hamadryas with attenuated VEE virus (strain 15) causes seroconversion in 100% of animals. Postvaccinal reaction such as viremia and short-lasting fever occurs in response to the injection of 10(3) ImD50 in about 30% of animals. CNS lesion symptoms characterizing infection of Papio hamadryas with natural Trinidad strain do not occur in response to injection with attenuated strain.
Subject(s)
Encephalitis Virus, Venezuelan Equine/immunology , Papio/immunology , Viral Vaccines/adverse effects , Animals , Dose-Response Relationship, Immunologic , Drug Evaluation, Preclinical , Encephalitis Virus, Venezuelan Equine/pathogenicity , Encephalomyelitis, Venezuelan Equine/immunology , Encephalomyelitis, Venezuelan Equine/prevention & control , Fever/etiology , Immunization/methods , Vaccines, Attenuated/administration & dosage , Vaccines, Attenuated/adverse effects , Vaccines, Attenuated/immunology , Viral Vaccines/administration & dosage , Viral Vaccines/immunology , Viremia/etiologyABSTRACT
The comparison of the polypeptide composition of 3 vaccinia virus strains, L-IVP, B-51 and CM-63, has revealed that strains L-IVP and B-51 are similar in their polypeptide composition, while in strain CM-63 capsid polypeptide with a molecular weight of 34000 daltons is absent or has altered electrophoretic mobility. As the result of the isolation of vaccinia envelopes (from strain L-IVP) and the electrophoretic separation of their polypeptides in plates with polyacrylamide gel 10 polypeptides have been obtained in 7 fractions, each containing 1 or 2 polypeptides. The immunization of rabbits with individual fractions has demonstrated that the formation of virus-neutralizing antibodies is induced mainly by 4-5 polypeptides in 3 fractions, having the highest molecular weight (54000-31000 daltons) and constituting about 19% of all proteins in the whole virion. The low-molecular envelopes polypeptides have been found to play no essential role in inducing the formation of virus-neutralizing antibodies. The highest antibody titers (1: 15625) have been detected in antisera to the preparations of whole vaccinia virus envelopes.
