PROTECTION OF GERM-FREE MICE FROM INFECTION BY HELICOBACTER-FELIS AFTER ACTIVE ORAL OR PASSIVE IGA IMMUNIZATION

Helicobacter pylori infection of human gastric epithelium has been ass ociated with gastritis, ulcers and gastric cancers. In an H. felis, ge rm-free mouse model of infection, oral immunization with bacterial ant igens plus cholera toxin resulted in elevated serum, gastric and intes tinal anti-H. felis antibody titres and protection from acute infectio n. Mice given monoclonal IgA anti-H. felis antibody at the time of ini tial challenge were also protected from infection. These results demon strate that oral vaccination may be a feasible approach for the preven tion of H. pylori infection of humans.