1 Uemura N

Okamoto S

Yamamoto S

et al. Helicobacter pylori infection and the development of gastric cancer.

2 Herrero R

Park JY

Forman D The fight against gastric cancer—the IARC Working Group report.

3 Sutton P

Chionh YT Why can't we make an effective vaccine against Helicobacter pylori?.

4 Michetti P

Kreiss C

Kotloff KL

et al. Oral immunization with urease and Escherichia coli heat-labile enterotoxin is safe and immunogenic in Helicobacter pylori-infected adults.

5 Zeng M

Mao Z-H

Li J-X

et al. Efficacy, safety, and immunogenicity of an oral recombinant Helicobacter pylori vaccine in children in China: a randomised, double-blind, placebo-controlled, phase 3 trial.

For a quarter of a century, countless attempts have been made to produce an effective vaccine against Helicobacter pylori, a major cause of peptic ulcer disease and gastric adenocarcinoma.An effective vaccine against H pylori is needed most for prevention of gastric adenocarcinoma, the third leading cause of cancer-related death worldwide.However, efforts to produce such a vaccine have so far failed, and H pylori vaccine research has slowed in the past few years. The main reason for this might have been disillusionment, arising from the inability to produce a vaccine that completely protects against the infection.Vaccine trials in mice have typically achieved only small reductions in the numbers of colonising H pylori. The story is similar in clinical trials, with only one showing potential efficacy, a small reduction in colonisation after therapeutic vaccination of infected volunteers.Hence, Ming Zeng and colleagues' publicationin The Lancet, of a randomised, double-blinded, placebo-controlled, phase 3 vaccine trial that shows a significant reduction in acquisition of natural H pylori infection, is a major advance.