FIG. 6.

Study 2 (monthly immunization): representative IHC results obtained with anti-VacA antibody on 4-μm-thick sections of formalin-fixed, paraffin-embedded gastric antral biopsies at the last sampling (week 23 postvaccination). The higher magnification at the right side of the right panel (group 4) shows positively stained H. pylori (solid arrowheads) within a glandular lumen, mostly aggregated, surrounded by several Gastrospirillum-like organisms VacA negative (empty arrowheads). Bar, 50 μm.