Detection of humoral and cell mediated immune responses among breeder ducks vaccinated against riemerellosis

Abstract

Riemerellosis is an infectious disease that primarily affects young ducklings, although it can infrequently be manifested in a chronic localised form in older ducks. Though an inactivated vaccine has been found to be most effective in preventing the disease in ducklings, its potency in adult breeder ducks has not been assessed yet. To investigate the same, 200 Kuttanad breeder ducks maintained in the University Poultry and Duck Farm (UPDF), Mannuthy were grouped into two, of 100 birds each, T1 being the control group and T2, the treatment (vaccinated) group. The oil-adjuvanted inactivated vaccine, prepared as per the previously standardised protocol, was administered to the T2 group in two doses, one week apart. Blood samples in serum vials, 20 each from T1 and T2, were collected on days 0, 14, 28, 56 and 90 post-immunisation (PI) whereas blood samples in heparin vials, eight each from both the groups, were collected on days 0, 14, and 28 PI. Humoral immunity (HI) and cell mediated immunity (CMI) in the adult ducks were assessed by enzyme-linked immunosorbent assay (ELISA) and lymphocyte proliferation assay (LPA), respectively. The two assays revealed that the inactivated vaccine elicited a good immune response in the adult ducks, with HI noticed until 90th day PI and an increasing CMI that peaked on 28th day PI.