An Edible Polyomavirus Vaccine

In this study, we investigate the hypothesis that food-grade vaccine antigens might be immunogenic when delivered via non-injection routes. Brewer’s yeast were engineered to express the VP1 major capsid protein of BK polyomavirus (BKV), as a model vaccine antigen. In support of conventional wisdom, purified VP1 or crude lysates of VP1-expressing yeast were not immunogenic when delivered to mice orally. Surprisingly, simply feeding mice live VP1-expressing yeast mixed with mouse chow induced robust antibody responses. In contrast to oral delivery, mice administered yeast lysates intranasally or intradermally mounted strong antibody responses to purified VP1. The neutralizing antibody titers of an author who home-brewed and drank live BKV VLP yeast increased from undetectable to moderate. The implications of these findings are revolutionary. Food-based vaccines are dramatically faster, easier, and cheaper to produce and are less painful than traditional injection vaccines. For some populations, edible vaccines may also be more acceptable and accessible than existing pharmaceutical products.