Abstract: An experimental vaccine was prepared by mixing commercial reovirus vaccine with antibody. Vaccines were inoculated into 18 day-old commercial broiler embryos at 0.1 of the recommended dose. At 3, 6, 9, 12 and 15 days post in ovo vaccination (PIOV), serum was collected and antibody against reovirus analyzed by an enzyme-linked immunosorbent assay (ELISA). At the same time, spleens were collected and vaccine virus detected by inoculating chicken embryo fibroblasts (CEF). At day 15 PIOV, chickens were challenged with a virulent reovirus S1133 strain. At day 25 PIOV, birds were euthanized and weighed. Efficacy was based on safety, antibody reaction, and percent (%) protection. Reovirus vaccine alone (vac) or complexed with antibody (AB) did not affect hatchability, morbidity, and mortality. Best protection was with the 2 experimental vaccine groups (73% for vac+1/16 dilution of AB) and (64% for vac+1/4 dilution of AB) provided by the vaccine mixed with 1:16 dilution of antibody. No vaccine resulted in an increase in antibody; however, titers of all challenged groups rose after challenge. Vaccine virus was detectable at day 3 PIOV in group 3 (vac+1/16AB) and 4 (vac) chickens. In contrast, vaccine virus detection was delayed until day 9 PIOV in group 2 (vac+1/4AB) chickens. The experimental antibody complex vaccine servers as a good starting point for development as a commercial vaccine.
Y. Guo , J. J. Giambrone , T. V. Dormitorio and Wu. Hongzhuan , 2003. Safety and Efficacy of In Ovo Administration of an Experimental Reovirus Vaccine in Commercial Broiler Chickens. Journal of Animal and Veterinary Advances, 2: 400-403.