THE VALUE OF DUCK-EMBRYO VACCINE AND HIGH-EGG-PASSAGE FLURY VACCINE IN EXPERIMENTAL RABIES INFECTION IN GUINEA-PIGS.

The authors have compared the value of multiple doses of duck-embryo and HEP Flury vaccine with that of pooled 5% sheep-brain vaccine in experimental rabies infection in guinea-pigs. They found that the duck-embryo vaccine given in a dosage corresponding to 14 ml of 10% vaccine (the dosage recommended for human treatment), either alone or with antirabies serum, gave no protection and that, even when administered in a dosage corresponding to 140 ml of 5% pooled vaccine, both the duck-embryo and the HEP Flury vaccines, whether alone or with serum, conferred little protection. Pooled phenolized vaccine under identical conditions gave good results. The immunogenicity of duck-embryo and HEP Flury vaccines, given before infection, was also inferior to that of pooled vaccine; and the duck-embryo vaccine was found to be a poorer antigen than the pooled vaccine in mouse potency tests.The authors conclude that the dosage of duck-embryo vaccine recommended for human treatment is inadequate and that the HEP Flury vaccine in its present form is unsuitable for post-infection treatment.