effect of maternally derived antibodies on the response of calves to vaccination against Kabete O rinderpest vaccine

ABSTRACT

A study was undertaken to find out the age at which calves borne to repeatedly vaccinated dame could be vaccinated against rinderpest [RP]. Eight vaccination regimes on eight groups of colostrums fed calves were implemented using a local live attenuated cell culture RP vaccine. The animals of regimes 1,2,3,4,5,6,7 and 8 were primary vaccinated at the age of 1,2,3,4,5,6,7 and 8 month respectively and boosted at the age of 6,7and 9 month in regimes 1 to 5 and at 9 months in regimes 6,7 and 8. Maternally derived antibody [MDA] and vaccine-induced antibody against rinderpest antigen were assessed using competitive ELISA and the detected antibodies are expressed as percent inhibition [PI] values. The sera that had P1 below 42 tested negative. Two days following feeding colostrum calves revealed highest PI [94.5-92.2]. MDA gradually declined to undetectable levels by the age of 4 to 6 months. Early vaccination regimes before the age of 6 months were ineffective ligier antibody levels were detected at the age of 7 months in the animals of regimes I,2,3,4,5 and one month after primary vaccination in regimes 6,7 and 8. Based on the above finding, it is recommended that the colostrum fed calves could be vaccinated against Rinderpest when they are at 6 to 7 months of age