RESUMEN
We report the findings of three randomized, double-blind, placebo-controlled Phase I studies undertaken to support licensure of the liquid formulation of the human G1P[8] rotavirus (RV) vaccine (RIX4414; GlaxoSmithKline Biologicals SA) in China. Healthy adults aged 18-45 y (n=48) and children aged 2-6 y (n=50) received a single dose of the human RV vaccine or placebo. Healthy infants (n=50) aged 6-16 weeks at the time of first vaccination received two oral doses of the human RV vaccine or placebo according to a 0, 1 mo schedule. In infants, blood samples were collected prior to vaccination and one month post-dose 2 to assess anti-RV IgA antibody concentrations using ELISA. Stool samples were collected from all infants on the day of each vaccination, at 7 and 15 d after each vaccination and one month post-dose 2. Stool samples were analyzed by ELISA for detection of RV antigen to assess RV antigen excretion. The reactogenicity profile of the human RV vaccine was found to be comparable to that of placebo in all age groups studied. The anti-RV IgA antibody seroconversion rate in infants after two vaccine doses was 86.7% (95% CI: 59.5-98.3). Vaccine take in infants who received the liquid human RV vaccine was 86.7% (95% CI: 59.5-98.3). A Phase III efficacy study of the human RV vaccine in the infant population in China has now been completed (ROTA-075/NCT01171963).