Researchers from Mayo Clinic and others say infant vaccine against rotavirus, which kills 500,000 each year in developing countries, has been shown in a Ghana study to be 60 percent effective.

According to Mayo, rotavirus causes fever, vomiting and diarrhea that can lead to severe dehydration in infants. Research results appear in the Journal of Infectious Diseases.

The goal is to protect infants before the time when toddler-safe vaccines can be given.

A total of 998 newborns In Ghana were part of the randomized, double-blind, placebo trial from two of the poorest parts of the country. Half got oral reassortant rotavirus tetravalent vaccine (RRV-TV) in the first two months of life. Half got placebo.

"Results showed a significant response in parameters of efficacy, safety and immune impact of the vaccine," says a Mayo study description.