Vaxart Inc.

One reason that oral vaccines are so rare is that, generally speaking, the immune system in the gut does not respond to foreign proteins such as food or normal bacteria. Vaxart Inc. has developed an oral vaccine system based on a key immune receptor that recognizes a signal for viral infection that is not normal in the gut and can therefore elicit a strong immune response. The vaccine platform targets toll-like receptor 3 (TLR-3), which occurs on the surface of cells in the small intestine. TLR-3 binds to double-stranded RNA, which is only found in double-stranded RNA viruses, and then alerts the immune system to the presence of the invader.