Stool samples were tested for rotavirus by enzyme-linked immunoglobulin assay (ELISA;

Rotaclone, Meridian Bioscience). Rotavirus-positive samples were tested at DDL Diagnostic Laboratory (Voorburg, the Netherlands) by reverse transcriptase polymerase chain reaction (RT-PCR), followed by reverse hybridization assay and/or sequencing in order to determine the rotavirus G and P genotypes and to differentiate presence of wild-type G1 rotavirus from the vaccine-strain virus [15]. Vaccine efficacy in the first Antidiabetic Compound Library cell line year of life has been reported for both cohorts in the initial analysis [3], however, Cohort 1 subjects were not included in the second-year efficacy follow-up period as they had terminated study participation before the protocol was amended to evaluate the efficacy of HRV over 2 consecutive rotavirus seasons. This report consequently

focuses on vaccine efficacy over two consecutive rotavirus seasons in Cohort 2 of the study, which involved follow-up until the end of the 2007 rotavirus season. The severity of all gastroenteritis episodes was evaluated with the use of the 20-point Vesikari scale, on which a score of 11 or more indicates severe gastroenteritis [16]. Vaccine efficacy was also measured for rotavirus-confirmed gastroenteritis of any severity, all-cause gastroenteritis, and all-cause severe gastroenteritis. Blood samples were collected from approximately 10% of infants in Cohort 1 prior to the first dose of study drug and one month after however the last dose of study drug had been administered, IWR-1 in vitro to determine serum concentrations of anti-rotavirus immunoglobulin A (IgA) antibody. We have previously reported on the IgA seropositivity rates for the pooled analysis of either 2 or 3 doses of HRV [3], however, we now extend this analysis to report on the immunogenicity of the HRV_2D and HRV_3D arms of the study. Serum from blood

samples were stored at −70 °C until being analyzed by ELISA at GlaxoSmithKline Biologicals, with the assay cutoff point set at 20 U/mL [17] and [18]. A randomization list was generated at GSK Biologicals, Rixensart, using a standard SAS® program (SAS Institute, Cary, NC, USA). A randomization blocking scheme (1:1:1 ratio) was used to ensure that balance between treatments was maintained throughout the study. The vaccine doses were distributed to each study center while respecting the randomization block size. The targeted sample size of 4950 participants between the South African and Malawi sites was based on evaluating the primary objective of determining if HRV (pooled HRV_2D and HRV_3D groups) given concomitantly with routine childhood vaccines could prevent S-RVGE (≥11 on the 20-point Vesikari scoring system) [16] caused by the circulating wild-type RV strains during the period from 2 weeks after the last dose of HRV vaccine or placebo until 1 year of age (after the first rotavirus season).