Neutralizing antibody responses of humans and mice to vaccination with Venezuelan encephalitis (TC-83) virus.

Laboratory workers were vaccinated with Venezuelan encephalitis virus, strain TC-83. After 2 to 3 years, they were bled, and their sera were tested for neutralizing antibody to all known Venezuelan encephalitis subtypes and varieties. The results indicated higher titers to epizootic than to enzootic Venezuelan encephalitis viruses and suggested that individuals vaccinated with TC-83 do not produce significant neutralizing antibody to heterologous subtypes. Mice vaccinated, bled, and tested in a similar manner produced much the same antibody profiles as did the humans and resisted challenge with all Venezuelan encephalitis viruses tested. In addition, the serum dilution plaque reduction neutralization test used was shown to be highly specific and adequate for diagnosis of infections with Venezuelan encephalitis viruses.