An experimental vaccine has been shown in a small study to protect people from norovirus, infamous for sickening hundreds in outbreaks aboard cruise ships.
Noroviruses spread from person to person and through contaminated food or water, causing diarrhea, vomiting and stomach pain. The infection causes more than 20 million cases of acute gastroenteritis annually in the United States, and there is no treatment.
Researchers tested a vaccine containing a weakened, non-infectious version of the virus in hopes that it would prompt a protective immune response in humans. Seventy-seven healthy men and women ages 18 to 50 participated. In two doses given three weeks apart, 38 subjects received the vaccine and 39 an inactive placebo. The results appeared in a recent issue of The New England Journal of Medicine.
After the second dose, all volunteers drank a liquid containing norovirus. Infection and illness developed in 37 percent of those who received the vaccine, compared with 69 percent of those who took the placebo. Among those infected, the illness was less severe and of shorter duration in the vaccine group, and the vaccine had no serious side effects.
Still, a marketable vaccine is years away, according to Dr. Robert L. Atmar, the lead author of the study and professor of medicine at Baylor. “What this shows is a proof of principle that norovirus can be prevented through vaccination,” he said.
New England Journal of Medicine & New York Times