Groups of 6 Balb/c mice were left unimmunized (PBS) or were immunized intranasally 4 times with 100 µg of <i>H. pylori</i> lysate+5 µg of CT adjuvant, 100 µg of Hp UreB237–251+5 µg of CT adjuvant, 100 µg of Hp UreB546–561+5 µg of CT adjuvant or a mixture of the two peptides (50 µg each)+5 µg of CT adjuvant, as described in the Methods section.

<p>Four weeks after completion of immunizations all mice were challenged twice over three days with ca 2×10⁷ cfu of <i>H. pylori</i> SS-1 and <b>3</b> weeks later mice were killed and recall splenic IFNγ responses in supernatants from lysate stimulated cultures with unstimulated background controls subtracted (A), serum IgG anti-<i>H. pylori</i> antibody responses (B) and gastric <i>H. pylori</i> cfu/g of stomach tissue (C) were determined. These are representive data from at least 3 identical experiments giving similar results. ANOVA was used for statistical analysis: * p<0.05, ** p<0.01 and ***p<0.001.