Vaccine against distemper and a process for its preparation

Live-virus vaccine against distemper in carnivores and process for its preparation. The vaccine in question preferably consists of a freeze- dried mixture of a virus and a stabilizer. The virus in the vaccine is one that is registered in the Pasteur Institute under number I-129 and is an attenuated strain of a virus causing distemper in carnivorous animals. This strain is prepared from a wild virus isolated from a mink with distemper by repeated passages in cell cultures of different origins. One of these cultures comes from canine kidneys, another from the kidneys of a human Rh embryo, and a third is a mixed cell culture consisting of cells from canine kidneys and cells from a Japanese quail embryo, this strain having been adapted to the cell culture of the embryo of a Japanese quail embryo and cultured on this medium. In the process for the preparation of the vaccine, an attenuated strain of the distemper virus causing this disease in carnivores is cultured in a cell culture on a nutrient medium, the virus-containing liquid is collected, and the said liquid is then freeze-dried (lyophilized) in the presence of a stabilizer. The process is characterized in that the attenuated virus strain is a virus that is registered in the Pasteur Institute under number I-129 and is one causing distemper in carnivores. It is obtained from a wild-type virus isolated from the blood of a mink with distemper. This procedure involves the following steps: a) a 20-40-fold passage in a cell culture from canine kidneys at a temperature of 37 +/- 1 degrees C, b) a 5-15 fold passage in a cell culture from Rh human embryo kidneys at a temperature of 32 +/- 1 degrees C, c) a 2-7 fold passage in a mixed cell culture consisting of cells from canine kidneys and cells from a Japanese quail embryo at a temperature of 35 +/- 1 degrees C, and finally d) adaptation by a 4-10 fold passage in a cell culture from a Japanese quail embryo. The advantages of the vaccine thus obtained are e.g. that it is not harmful and that it has a high immunogenic and antigenic activity. The vaccine does not contain any alien viruses and can be used for the prophylactic treatment of distemper in carnivores and for eliminating epizootic infections. The vaccine can also be used in aerosol form.