Experimental evaluation of an inactivated vaccine against chicken anaemia virus

Summary An assessment of the performance of an inactivated chicken anaemia virus (CAV) vaccine following administration to specific‐pathogen‐free (SPF) breeder hens before the egg production period is reported. Antibodies to CAV in adult hens and maternally‐derived antibodies to CAV in the progeny chicks were assayed by ELISA. Progeny of vaccinated chickens showed sufficient levels of maternally‐derived antibody to CAV for up to 3 to 4 weeks of age. Following challenge at 1, 10, 20 and 30 days of age of chicks from CAV‐vaccinated and non‐vaccinated hens with virulent CAV, haematocrit levels and weights of thymus in vaccinates remained within normal ranges. Chicks derived from non‐vaccinated hens developed anaemia and thymus atrophy following challenge. These results support the view that vaccination of breeder flocks with an inactivated vaccine to CAV could be an effective means of control of CAV‐induced clinical disease.