The rotavirus vaccine protects infants from rotavirus, a highly contagious virus causing severe watery diarrhea, vomiting, and dehydration. Benefits: It is highly effective at preventing severe gastrointestinal illness and significantly reduces the risk of hospitalization. Administration Schedule: This vaccine is given orally as liquid drops in the mouth, not as a shot. It is administered in either a 2-dose or 3-dose series: First dose: Given at 2 months of age (must be administered before 15 weeks). Remaining doses: Given at 4 months (and 6 months, if a 3-dose series is used). All doses must be completed by 8 months of age.