Clinical Question: Is an oral vaccine safe and effective for the prevention of rotavirus infection in young children?

Setting: Population-based

Study Design: Randomized controlled trial (double-blinded)

Allocation: Uncertain

Synopsis: The first vaccine for rotavirus (Rotashield) was withdrawn from the market because it caused intussusception in rare cases. This study evaluated a live attenuated vaccine (Rotarix, not yet approved for use in the United States) given in two oral doses, one to two months apart, with the first dose given to patients between six and 13 weeks of age. The study randomized more than 62,000 infants, to the vaccine or placebo, in Finland and in 11 South American and Central American countries. Allocation concealment and randomization procedures are not clearly described by the authors.

The group was followed up for a median of 100 days to assess the safety of the vaccine, and a subgroup of 20,169 infants was followed for nine to 10 months to evaluate effectiveness. There was no significant difference between groups in the likelihood of intussusception (nine in the vaccine group and 16 in the placebo group). Regarding effectiveness, the risk of severe gastroenteritis from any cause (defined using a standard symptoms scale) was reduced from 52 to 31 episodes per 1,000 infants per year (number needed to treat [NNT] = 48; 95% confidence interval [CI], 26 to 303), and the number of diarrhea-related hospitalizations was reduced from 42 to 25 episodes per 1,000 infants per year (NNT = 56; 95% CI, 29 to 486). Both of these differences were statistically significant. A second study in the same journal issue reported similar findings for a second oral vaccine (Rotateq) given in three doses (Vesikari T, et al.; for the Rotavirus Efficacy and Safety Trial [REST] Study Team. Safety and efficacy of a pentavalent humanbovine [WC3] reassortant rotavirus vaccine. N Engl J Med 2006;354:23–33).

Bottom Line: Oral vaccines have been developed that are safe and effective for the prevention of rotavirus in young children. This will be particularly useful in developing countries, where this disease is a major cause of infant mortality. (Level of Evidence: 1b)