Protection of Cattle Against Lumpy Skin Disease: I.—Trials with a Vaccine Against Neethling Type Infection

Abstract

SUMMARY It is shown that 3 strains of sheep pox will protect cattle against experimental lumpy skin disease infection. The reasons for the choice of the “Kedong” strain of sheep pox as a vaccinating agent are given. The 50 per cent protective dose (PD50) for cattle was found to consist of eight point nine 50 per cent infective doses for tissue culture (TCID50). The size of the field dose of vaccine chosen was approximately 9,000 PD50 per animal. Safety trials of vaccine produced from a stock pool of virus are described. No spread of virus from cattle to sheep was demonstrated and alternate cattle/sheep passage was unsuccessful. In approximately 1,000 cattle no severe local reactions occurred. The vaccine was issued for experimental field use in 1959 and over 111,000 doses were used. The precautions to be taken during field use and the results of a survey of 57 vaccinated farms are detailed. Local reactions were observed in 0.3 per cent of the vaccinated cattle. On 10 farms vaccinated cattle were herded with sheep but there was no outbreak of sheep pox on the vaccinated farms. The use of sheep pox virus as a vaccinating agent against lumpy skin disease in cattle is discussed.