Phase II year
1995
(last award dollars: 1996)
We will develop mucosally administered vaccines against Helicobacter pylori infection to prevent the consequences of chronic H. pylori infection which may include gastritis, duodenal ulceration, and gastric carcinoma. One vaccine would dicit an immune response that would protect against primary infection and a second vaccine would dicit an immune response that would assist an infected individual in clearing the infection. Our Phase I study showed that immunization with a recombinant urease apoenzyme from H. pylori protected mice against challenge with Helicobacter felis.- Phase II has several specific aims: (i) confirm and more fully characterize these observations in mice by determining dose requirements, route of immunization, requirement for adjuvants, duration of protection and mechanism of protection; (ii) extend the observation on urease in H. pylori animal models, and (iii) conduct a clinical trial to assess tolerability and to obtain data on immunogenicity in humans.National Institute of Allergy and Infectious Diseases (NIAID)