Oral immunization against Helicobacter pylori--a future concept.

The demonstration that oral immunization with lysates of Helicobacter or with Helicobacter pylori urease can protect mice against H. felis infection opened the field of vaccine development against Helicobacter infections. More recently, the same antigen preparations were used successfully as a therapeutic vaccine able to cure the infection, and additional protective antigens were identified. Evidence from animal studies suggests that protection is medicated by mucosal antibodies, in association with a T helper type 2 cell cellular immune response. Vaccine adjuvants, delivery systems, and therapeutic vaccination are likely to be the areas of major progress in the future.