SAFETY, IMMUNOGENICITY, AND PROTECTIVE EFFICACY OF ONE AND 3 DOSES OFTHE TETRAVALENT RHESUS ROTAVIRUS VACCINE IN INFANTS IN LIMA, PERU

An oral rhesus-human rotavirus tetravalent (RRV-TV) vaccine (10(4) pfu of rhesus rotavirus [type G3] and of 3 human-rhesus reassortants [G1, G2, and G4]) was evaluated in a field trial in Lima, Peru. At 2, 3, a nd 4 months of age, infants received either a dose of RRV-TV, an initi al dose of vaccine followed by a dose of placebo at 3 and 4 months, or a dose of placebo. Rotavirus-specific IgA responses were detected by ELISA in 75% of the three-dose vaccine group, 59% of the one-dose vacc ine group (P = .05), and 24% of the placebo group (P < .001): 64%, 48% , and 12% of each group, respectively, had a neutralizing antibody res ponse to at least 1 serotype. Both one and three doses of vaccine fail ed to induce a significant level of protection against rotavirus diarr hea; however, they did provide some protection (range, 35%-66%) agains t more severe rotavirus diarrhea, especially for episodes caused by ty pe G1.