The effect of rotavirus immunization on rotavirus gastroenteritis hospitalization rates in military dependents.

We conducted a retrospective review of all U.S. military dependents less than 5 years old hospitalized with rotavirus-associated gastroenteritis from July 2003 to June 2009. The two post-vaccine seasons showed a significant reduction of 62.4% (95% CI, 58.6-65.8, P<0.001) in rotavirus gastroenteritis hospitalization rate compared to the three pre-vaccine seasons. Infants less than 12 months old showed the greatest reduction in incidence at 75.3%. A substantial decrease was also seen in unvaccinated children as well. Vaccine efficacy against hospitalization was 86.0% (95% CI, 77.7-91.3) after just a single dose. The overwhelming majority of children hospitalized for rotavirus since the introduction of the vaccine (ranging from 91.8 to 100% per season) had not received any of the rotavirus vaccine series.