Recombinant Vaccinia-Venezuelan Equine Encephalomyelitis (VEE) Vaccine ProtectsNonhuman Primates against Parenteral and Intranasal Challenge with Virulent VEE Virus

摘要

VEE vaccines presently available for human use have several important drawbacks,including reactogenicity, poor immunogenicity, and potential teratogenicity. A recombinant vaccinia virus (designated TC-5A) encoding the structural protein region of VEE virus was used to immunize cynomolgus monkeys. The primary humoral immune response was similar in magnitude and chronology to that of monkeys given two doses of formalin-inactivated C-84 VEE vaccine, but inferior to that of animals given live attenuated TC-83 VEE vaccine. Monkeys immunized with TC-83 vaccine were solidly protected against challenge with a virulent VEE virus by the subcutaneous (s.c.), intranasal (i.n.), and intracerebral (i.c.) routes. Protection by recombinant TC-5A and inactivated C-84 vaccines was less complete, but viremia titers were delayed and of lower magnitude in all monkeys. Complete protection (absent viremia and leukopenia, no antibody boost to challenge) was