Effectiveness of pentavalent rotavirus vaccine against severe disease.

OBJECTIVE: To determine the vaccine effectiveness (VE) of complete and partial vaccination with the pentavalent rotavirus vaccine (RV5) in the prevention of rotavirus acute gastroenteritis (AGE) hospitalizations and emergency department visits during the first 3 rotavirus seasons after vaccine introduction.
METHODS: Active, prospective population-based surveillance for AGE and acute respiratory infection (ARIs) in inpatient and emergency department settings provided subjects for a case-control evaluation of VE in 3 US counties from January 2006 through June 2009. Children with laboratory-confirmed rotavirus AGE (cases) were matched according to date of birth and onset of illness to 2 sets of controls: children with rotavirus-negative AGE and children with ARI. The main outcome measure was VE with complete (3 doses) or partial (1 or 2 doses) RV5 vaccination.
RESULTS: Of age-eligible children enrolled, 18% of cases, 54% of AGE controls, and 54% of ARI controls received ≥1 dose of RV5. The VE of RV5 for 1, 2, and 3 doses against all rotavirus genotypes with the use of rotavirus-negative AGE controls was 74% (95% confidence interval [CI]: 37%-90%), 88% (95% CI: 66%-96%), and 87% (95% CI: 71%-94%), respectively, and with the use of ARI controls was 73% (95% CI: 43%-88%), 88% (95% CI: 68%-95%), and 85% (95% CI: 72%-91%), respectively. The overall VE estimates were comparable during the first and second years of life and against AGE caused by different rotavirus strains.
CONCLUSION: RV5 was highly effective in preventing severe rotavirus disease, even after a partial series, with protection persisting throughout the second year of life.