Biological modification of rabies virus as a result of its adaptation to chicks and developing chick embryos.

This article describes experiments indicating a change in pathogenicity for laboratory animals of the Flury strain of rabies virus at high egg passages. Factors such as dilution of virus, number of egg passages, age of animals, and route of inoculation are taken into account. The results of the author's investigations indicate that living chick-embryo-adapted virus can be used both as a vaccine administered before exposure to rabies virus, and as an adjunct to antiserum in the protective treatment of animals after exposure.