Generation and evaluation of a recombinant modified vaccinia virus Ankara vaccine for rabies.

Modified vaccinia virus Ankara (MVA) has become a vaccine vector of choice for recombinant vaccine development. A MVA-based rabies vaccine would be advantageous for use as a vaccine for dogs (and wildlife), particularly if it proves innocuous and efficacious by the oral route. Here, the generation and immunological testing of a recombinant MVA expressing a rabies virus glycoprotein gene is described. In a murine model, higher dosages of recombinant MVA were needed to induce equivocal immune responses as with Vaccinia Copenhagen or Vaccinia Western Reserve recombinants, when administered by a parenteral route. The MVA recombinant was not immunogenic or efficacious when administered per os in naïve mice. The ability of the recombinant MVA to induce anamnestic responses in dogs and raccoons was also investigated. Recombinant MVA boosted humoral immune responses in these animals when administered peripherally, but not when administered orally.