Researchers from Mayo Clinic and other institutions have shown that a vaccine given to newborns is at least 60 percent effective against rotavirus in Ghana. Rotavirus causes fever, vomiting and diarrhea, which in infants can cause severe dehydration. In developed nations, the condition often results in an emergency room visit or an occasional hospitalization, but is rarely fatal. In developing countries, however, rotavirus-related illness causes approximately 500,000 deaths per year. The findings appear this week in the Journal of Infectious Diseases.