Serological responses in commercial chicken to a Newcastle Disease I2 thermostable vaccine in Uganda.

Abstract

A locally- produced Newcastle Disease (NCD) I₂ thermostable vaccine of embryo - infective dose (EID. ) of 10^8.5 per ml. was administered to 100 laboratory chicken in four groups, each of 25 birds, by eye drop method, I₂E; in water previously boiled and cooled, WA; same water but freshly medicated with an adequate dose of Levamisole, LE; and using millet grains previously roasted and cooled as vaccine carrier, Ml, A fifth group, LA, also consisting of 25 birds received heat- sensitive Lasota vaccine by eyedrop, as a control group. The immunological responses were monitored by Enzyme - linked immunosorbent assay (ELISA) Newcastle disease antibody (Ab) technique on sera samples from 18 randomly selected birds in each group at 3-week intervals for a 3 month period. The overall mean percentage positivities and antibody log₁₀ titres in each group respectively were: I₂E, 85.75%, 3.10; WA, 70.2%, 2.91; LE 82.7%, 3.02; M1 87% , 3.17 and LA, 87.25%, 3.29. During the first 3 weeks, there was a significant difference in response between birds given the I₂ vaccine by eyedrop and using water alone as did that between birds vaccinated using millet grains and either water alone or medicated with Levamisole. Lasota vaccine produced a significantly higher response than that by the I₂ vaccine given either in water alone or medicated with Levamisole. At 3 months, the response to Lasota vaccine was significantly higher than that to the I₂ Vaccine given either by eyedrop or millet grains.
Throughout the study period, the I₂ vaccine did not produce significant differences in response between birds vaccinated using water alone and that medicated with Levamisole. It was concluded that there is a possibility of providing combined treatment in chicken against worms using oral levamisole and vaccination with the I₂ NCD thermostable vaccine in drinking water. Millet is potentially a good I₂ vaccine carrier. NCD I₂ vaccine given by eyedrop is more effective than by use of drinking water.