DUCK-EMBRYO RABIES VACCINE

Abstract

† Improvements in the methods of immunizing against rabies are needed because neuroparalytic accidents are known to have occurred following the use of present methods. The use of embryonated duck eggs in place of rabbit brain for propagating the virus eliminates the myelin, which has been suspected of contributing to the nervous complications. The animal experiments here described showed that duck-embryo rabies vaccine could be killed by dilutions of beta-propiolactone not exceeding 1:4,000. Killed under these conditions, the virus was shown to be antigenic in mice. Detectable antibody appeared between 7 and 10 days after the first inoculation and continued to be present on the 15th and 30th days. In treating bites of rabid animals, antibody must be made to appear as early as possible. The absence of brain tissue in this preparation has distinct advantages.