APPROACHES TO FOOD-BASED VACCINES FOR DOMESTIC CHICKENS

Domestic chickens were fed viral vaccines that were applied to the sur face of food pellets, Responses were judged by the production of speci fic antibodies, and compared with the responses obtained when the same vaccines were given by conventional routes. Chickens responded simila rly to commercial avian infectious encephalomyelitis vaccine given on food or by eyedrop when antibodies were measured by ELISA, and the vac cine virus spread by contact. Increasing the dose of oral vaccine tenf old gave a more rapid serological response but the levels of antibody were not increased. There was no serological response to commercial in fectious laryngotracheitis virus vaccine given on food. An experimenta l avian adenovirus vaccine produced a serological response when given on food, but higher levels of antibody were produced in response to va ccination by eyedrop. The vaccine virus spread by contact. It was conc luded that current avian infectious encephalomyelitis vaccines, and pr ospective recombinant vaccines based on avian adenovirus vectors, coul d be delivered on food.