DAVIS, Calif., July 17 U.S. scientists have developed immunization methods that can offer long-term protection against Helicobacter pylori infections.
University of California-Davis researchers said the new methods might also contribute to a possible ulcer vaccine.
H. pylori is a bacterium colonizing the digestive tract of 50 percent of the world's population. Infection can lead to chronic gastritis, peptic ulcer disease and gastric cancer. But expensive antibiotics currently used against H. pylori are encountering increasing resistance.
In the University of California-Davis study, mice were immunized in four groups: orally alone, intramuscularly alone, orally followed by intramuscularly, and intramuscularly followed by orally and then challenged orally with H. pylori after three months. The researchers found mice receiving intramuscular immunization alone or a combination of oral and intramuscular vaccinations had significantly reduced bacterial loads and no detectible H. pylori in their intestinal tract.
Mice immunized just orally or intramuscularly followed by orally weren't protected and had decreased antibody responses.
"This study demonstrates the ability to induce long-term immunity against H. pylori, provides correlates of protection, and illustrates the crucial role of the immunization route(s)," said the researchers.
The research appears in the July issue of the journal Infection and Immunity.
Copyright 2007 by UPI
