How do vaccines against rotavirus protect infants from severe diarrhea?

Rotavirus is a major cause of severe diarrhea in infants and young children, especially where access to hospital care is limited. The oral vaccine is given early in life so the immune system can respond before the child is exposed to the virus. By reducing severe gastroenteritis, the vaccine helps prevent dehydration, hospitalization, and death. Since rotavirus vaccination was introduced in many countries, hospital admissions for severe diarrhea in children have dropped substantially. The vaccine is part of routine infant immunization schedules in many parts of the world.