This was a randomized, double-blinded, placebo-controlled trial. During 1993 to 1994, at 10 US study sites, 439 healthy infants 2 to 6 months of age, were enrolled to receive 3 doses of oral QRV or placebo at approximately 8-week intervals.
The vaccine was generally well tolerated; no serious vaccine-related adverse experiences were reported. Risk differences and 95 % confidence intervals suggested no differences between vaccine and placebo recipients in the incidences of fever, irritability, vomiting, or diarrhea during the 14 days after any dose. QRV was 74.6 % efficacious (95 % CI: 49.5 % , 88.3 % ) in preventing rotavirus acute gastroenteritis (AGE), regardless of severity and 100 % efficacious (95 % CI: 43.5 % , 100 % ) in preventing severe rotavirus AGE through one rotavirus season. Serotype G1 was identified in most infants with rotavirus AGE. A ≥3-fold rise in serum neutralizing antibody to G1 was observed in 57 % (45/79) of vaccinees. A ≥3-fold rise in serum anti-rotavirus IgA and fecal anti-rotavirus IgA was observed in 88 % (162/185) and 65 % (104/159) of vaccinees, respectively.
QRV was generally well tolerated, immungenic, and highly effective against rotavirus gastroenteritis.