rotaviruses Enteroviridae viruses that are the leading recognized cause of diarrhoea-related illness and death in infants and young children. A live attenuated vaccine is available and provides excellent protection against severe rotavirus gastroenteritis. A pentavalent human-bovine reassortant rotavirus vaccine is also available. This protects against the four most prevalent human strains. The name of the virus derives from the wheel-like appearance on electron microscopy.