A rotavirus vaccine protects children from rotaviruses, which are the leading cause of severe diarrhoea among infants and young children. Nearly every child in the world will suffer an episode of diarrhea caused by rotavirus before age five. Rotavirus A, the most common, causes more than 90% of infections in humans. In 2006, two vaccines against rotavirus A infection were shown to be safe and effective in children: Rotarix and RotaTeq. Both are taken orally and contain disabled live virus.