Protectivity and Antibody Response of Seven Avian Reovirus Live Vaccines in SPF Chickens

Abstract

Live avian reovirus (ARV) vaccine has long been using in poultry industry. Safety, protectivity and antibody response of each individual vaccine is still not clear. Seven commercial live ARV vaccines were each administrated subcutanously twice to 7 groups of 20 SPF chickens at 1 and 5 weeks of age. A control group was also included in this experiment. Blood from all chickens were collected at 3 and 7 weeks of age for ARV enzyme-linked immunosorbent assay (ELISA) antibody test. At 9-week-old, 10 birds per group were challenged via the footpad with the 1733 and 2408 strains of ARV. The increase in the footpad thickness and swelling at 7 and 14 days post challenge (DPC) were calculated. AII vaccinated birds were survived in good health. At 3 and 7 weeks of age, 1 (14.2%) and 6 (85.5%) vaccinated groups of chickens had geometric mean ELlSA titers (GMT) in excess of 1:1000 respectively. At 7 and 14 DPC, 2 and 1 vaccinated group had the increase of footpad swelling in millimeter significantly (P＜0.05) less than the control group. AII the vaccinated groups had footpad swellings and leg hemorrhage scores significantly (P＜0.05) less than the control group. Commercial live ARV vaccines provide some protectivity against virulent ARV challenge, but the protectivity is the remaining virulence of vaccine virus corelated.