Adverse reactions in cattle after vaccination with lapinized rinderpest virus

Abstract

A survey embracing all cattle vaccinated in Kenya with lapinized rinderpest virus between 1 January 1954 and 30 June 1956 revealed an over-all incidence rate of adverse reactions of 0·09 %. The real incidence rate approached 3 per 1000 cattle because only susceptible cattle were at risk. Four types of reactions were recognized. The most serious, because of the attendant high case mortality rate, was aggravation of latent protozoal infections. The commonest reactions were rinderpest-like without serious sequelae except in pregnant cows, many of which aborted. Transient spermatolysis was observed in six vaccinated bulls and anaphylaxis was recorded rarely.The incidence of rinderpest-like reactions was primarily influenced by the innate resistance of the cattle. The viral strains recovered from reacting cattle were genotypically unchanged.I am grateful to Mr J. W. Macaulay, B.Sc., F.R.C.V.S., D.V.S.M., Chief Veterinary Research Officer, Kabete, Kenya, for his encouragement, advice and counsel. This paper is published by permission of the Director of Veterinary Services, Kenya.