SAFETY, IMMUNOGENICITY, AND EFFICACY OF AN INACTIVATED AVIAN POLYOMAVIRUS VACCINE

Objective-To determine safety, immunogenicity, and efficacy of an inac tivated avian polyomavirus vaccine in nonbudgerigar psittacine birds t hat varied in age, species, and immunologic status. Animals-Safety of the vaccine was evaluated in 1,823 psittacines representing more than 80 species. Immunogenicity was evaluated in 285 birds (260 of various Psittaciformes species, 25 chickens). Efficacy was evaluated in 104 bi rds (78 of various Psittaciformes species, 26 chickens). Procedures-Sa fety was evaluated by vaccinating birds that were determined to be ser onegative or seropositive (titer > 1:10) prior to vaccination. Birds w ere then evaluated for clinically detectable systemic or local reactio ns for 2 months to 2 years. immunogenicity was evaluated by testing fo r virus-neutralizing antibodies, vaccinating each bird twice, and then testing for a significant change in antibody titer. Efficacy was eval uated by vaccinating birds, followed in 2 to 4 weeks by intramuscular or intravenous challenge exposure. After challenge exposure, protectio n was evaluated by attempting to recover virus from tissues or by obse rving birds for clinical signs of disease and testing for a significan t change in titer. Conclusions-Avian polyomavirus vaccine is safe, imm unogenic, and efficacious for use in multiple species of mature and im mature psittacines. Clinical Relevance-Until now, prevention of polyom avirus infection in psittacine birds could only be accomplished throug h strict isolation to reduce potential exposure to the virus. The USDA -registered inactivated avian polyomavirus vaccine can safely be used to protect vaccinates from infection and control spread of this virus in flocks.