This Phase 3 study was designed to evaluate the safety of the investigational rotavirus vaccine and the efficacy to prevent rotavirus gastroenteritis.
This study enrolled over 69,000 infants 6 to 12 weeks of age. The participants were broken into two groups, one to receive the vaccine the other group would receive a placebo.
The primary outcome measured the number of participants with confirmed intussusception within 42 days after each vaccination with RotaTeq™/placebo. as well as how many Rotavirus gastroenteritis cases occurred in all participants with one or more episodes classified as positive. Multiple positive episodes for one participant are counted as a single case.
The New England Journal of Medicine published the following results.
The 34,035 infants in the vaccine group and 34,003 in the placebo group were monitored for serious adverse events. Intussusception occurred in 12 vaccine recipients and 15 placebo recipients within one year after the first dose including six vaccine recipients and five placebo recipients within 42 days after any dose (relative risk, 1.6; 95 percent confidence interval, 0.4 to 6.4). The vaccine reduced hospitalizations and emergency department visits related to G1-G4 rotavirus gastroenteritis occurring 14 or more days after the third dose by 94.5 percent (95 percent confidence interval, 91.2 to 96.6 percent).
In a nested substudy, efficacy against any G1-G4 rotavirus gastroenteritis through the first full rotavirus season after vaccination was 74.0 percent (95 percent confidence interval, 66.8 to 79.9 percent); efficacy against severe gastroenteritis was 98.0 percent (95 percent confidence interval, 88.3 to 100 percent). The vaccine reduced clinic visits for G1-G4 rotavirus gastroenteritis by 86.0 percent (95 percent confidence interval, 73.9 to 92.5 percent).
This vaccine was efficacious in preventing rotavirus gastroenteritis, decreasing severe disease and health care contacts. The risk of intussusception was similar in vaccine and placebo recipients.