Fowl-pox vaccination in South Africa with egg-propagated fowl and pigeon-pox viruses

Abstract

1. Fowl-pox as it occurs in the Union of South Africa is reviewed briefly together with relevant literature on the methods of immunization. 2. In South Africa until recently vaccine prepared from virus propagated on pigeons has been used for immunization of poultry. The reasons for abandoning this vaccine are discussed. 3. The technique of propagating fowl- and pigeon-pox virus m eggs is discussed, attention being paid to :- (a) The influence of temperature of incubation; (b) The time allowed for multiplication; (c) The distribution of virus in the eggs; (d) The virus titre of infected membranes; (e) The isolation of pigeon-pox virus strains. 4. The preparation of fowl- and pigeon-pox virus vaccine is described with particular reference to : (a) Potency of the vaccine and its estimation; (b) The keeping quality; (c) The correlation between infectivity for egg and for chickens.