Norovirus vaccine candidate cuts symptoms by more than half

A vaccine candidate for norovirus reduced the main symptoms of gastrointestinal infection, diarrhea and/or vomiting by 52 percent, according to research presented on Friday at IDWeek 2013.

There is currently no treatment or cure for norovirus, which is the most common cause of severe GI infection in the U.S. According to the U.S. Centers for Disease Control and Prevention, there are 19 million to 21 million Americans infected with the disease annually. The disease kills as many as 800 people in the U.S. each year.

"Norovirus truly is a global issue and most if not everyone has experienced it to some degree," David Bernstein, the lead author of the study, said. "The results of our study are promising and our next step is to test this vaccine in a real-world setting."

In a randomized, multi-center trial, researchers tested the investigational vaccine in 98 people who agreed to drink water containing norovirus. Sixty percent of the non-vaccine group became infected with the virus, while 52 percent became infected in the vaccine group. In the vaccine group, 20 percent suffered from mild, moderate or severe vomiting and/or diarrhea versus 42 percent in the non-vaccine group, representing a 52 percent reduction in symptoms.

Bernstein said that while not everyone who is exposed to norovirus becomes infected or expresses symptoms, the disease can be serious for children and older adults.

"If the vaccine continues to prove as effective as our initial results indicate, it could be used for specific populations or situations -- in those at a higher risk of severe disease such as the elderly or at high risk for infection or transmission such as in day care, people going on a cruise, those in nursing homes or in the military," Bernstein said. "Or it could be offered to everyone, since all of us are exposed at one time or another."