Chick-Embryo-Cell Inactivated Rabies Vaccine for Veterinary Use. Laboratory and Field Experience

Abstract

Continuing research in many parts of the world resulted in steadily increasing knowledge about the rabies virion, its behaviour in tissue culture, and the use of tissue culture procedures for vaccine production. Tissue culture vaccines for veterinary use appeared on the market towards the end of the sixties, and we survey about 15 years of experience with a tissue culture vaccine for veterinary use based on the Flury LEP-C23 strain as the vaccine strain, and primary chick embryo cells as the cell substrate. First the virus was inactivated by heat, later on by betapropio-lactone. Further development of this vaccine led to an antigen which was concentrated and purified by continuous density gradient centrifugation a purification method which so far has only been applied for vaccines for human use. By this method, pure and highly concentrated inactivated antigen concentrates are achieved which are evaluated by the modified antibody binding test and diluted to give a potent vaccine. This procedure has proved to be very valuable in the manufacture of vaccine batches with standardized potency in monovalent and combined vaccines. Some results from laboratory tests and from the field with these vaccines are reported.