Immunogenicity of Helicobacter pylori urease B protein and DNA vaccines in a mouse model

A vaccine could alleviate major morbidity and mortality associated with Helicobacter pylori infection. We immunized BALB/c mice with 3 doses of a protein or DNA vaccine based on H pylori urease B. Protein alone was immunogenic even after the first dose, whereas DNA did not elicit antibodies after 3 doses. DNA preceding protein (D-P-P) appeared to blunt the response to protein, whereas DNA following protein (P-D-D) shifted from a predominantly T helper 2 (Th2) profile to a balanced Th1:Th2 profile. These preliminary findings may have important implications for the development of an H pylori vaccine.