Process for preparing a vaccine comprising a combination of modified live virus distemper vaccine and modified live virus infectious hepatitis vaccine

摘要

A vaccine for simultaneously immunizing dogs against distemper and infectious hepatitis comprises a dry stable mixture of egg embryo infected with modified canine distemper virus, a canine tissue culture fluid containing modified canine infectious hepatitis virus and a sucrose glutamate buffer solution. The dry material may be diluted with distilled water or other suitable diluent prior to use. The vaccine may be prepared by mixing, in the presence of a suitable stabilizing agent, e.g. sucrose glutamate buffer solution, egg tissue infected with modified canine distemper virus with a tissue culture fluid containing live modified canine infectious hepatitis virus and subjecting the liquid mixture to freeze drying to produce a stable dry vaccine. The distemper virus is one that has been propagated in incubating embryonated eggs and serially passed through incubating eggs until the virus is modified to the extent that it will produce distemper in susceptible dogs but is capable of protecting dogs against distemper. The egg tissue may be poultry embryo tissue and the freeze dry treatment may comprise rapid freezing of the liquid mixture and drying from the frozen state. The embryonic egg tissue may be mixed with a sucrose glutamate buffer prior mixing with tissue culture fluid and may be present in amount of 10 parts by weight egg tissue, 20 parts by volume buffer and 1 part by volume of the tissue culture fluid.