Efficacy of chicken anemia vaccine in broiler parent stock

Abstract

Background: Chicken anemia virus (CAV) is an important poultry pathogen, which causes immunosuppression and varying levels of mortality. Poultry production is a major livelihood for the people in Bangladesh. The broiler parent stock of Bangladesh using vaccine against CAV but the efficacy of this vaccine against CAV is not well understood. The present study highlights the vaccine efficacy of CAV and maternal transfer of antibodies to the hatched chicks. Methods: Total 7 broiler parent stock (Cobb 500) farms were selected from 7 districts of Bangladesh. Vaccines against CAV administer single time at 80 days of age by live Nobilis® CAV P4 vaccine. Total 516 blood samples were collected in 6 times (at 0, 17, 25, 33, 41 and 49 weeks) from each farm. Then again 143 blood samples were collected from next generation broiler chicks of corresponding broiler parent stock farms at 0, 15 and 30 days. There was no CAV vaccine used in this broiler. Test methods were indirect ELISA test for the detection of blood antibody level against CAV by commercially available kits. Results: No adverse reactions were observed in any of the birds during the course of the study. Our results suggest that the CAV antibody starts decreasing 10 weeks post vaccination. Moreover, a substantial maternal antibody titer has been observed in all groups of chicken hatched out from the earlier vaccinated birds which is sufficient to protect up to first 30 days of life. Conclusions: The antibody titer against CAV become declined after 10 weeks of post vaccination to broiler parent stock and maternally derived antibody can protect chicks until 30 days of live. The study reports the efficacy of vaccination against CAV in Bangladesh and its possible implications in further optimizing the strategy for its vaccination.