When dose 1 was given at 6 weeks
of age, the seroconversion rate after the single dose was 13% (95% confidence interval [CI] = 6–25) in the group receiving concomitant OPV and 33% (95% CI = 21–46) in the IPV group. One month after the second dose of RIX4414, the seroconversion rates were 36% (95% CI = 23–50) in the OPV group compared to 43% (95% CI = 29–58) in the IPV group. When the vaccine doses were given later, at 10 and 14 weeks of age, IgA sero-conversion rates were 46% (95% CI = 31–63) (OPV group) and 62% (95% CI = 46–76) (IPV group) one month after the first dose; and 61% (95% CI = 39–70) (OPV group) and 55% (95% CI = 39–70) (IPV group) after the second dose. This difference was also reflected
in the geometric mean concentrations (GMC) of the antibody response. One month after the first dose of RIX4414 at 10 weeks of age, the OPV group FDA-approved Drug Library screening had lower antirotavirus IgA GMC (39 U/mL; 95% CI = 24–65) compared with the IPV group (65 U/mL; 95% CI = 37–114), for a difference of 40% (results for dose 1 at 6 weeks were not provided). After the second dose of RIX4414, this difference was smaller (49 U/mL and 57 U/mL respectively). In conclusion, while OPV affected the immune response to the first dose of rotavirus vaccination at both age regimens, after dose 2, immune responses to Rotarix™ among the OPV and IPV groups were similar for both age regimens. In the Selleck PI3K Inhibitor Library second study [31], the immune
response to Rotarix™, which has a higher vaccine titer (1 × 106.0 median cell culture infective dose) than the previously studied RIX4414 in South Africa [26], was evaluated in a 2-dose schedule (administered at 10 and 14 weeks of age) compared to a 3-dose schedule at 6, 10 and 14 weeks of age) [36]. OPV was administered concomitantly to all infants in this analysis. In the study, the seroconversion rate after the first dose of Rotarix™ given at tuclazepam 6 weeks of age, with OPV, was 19% (95% CI = 13–26). However, seroconversion after the first Rotarix™ dose at 10 weeks of age was not evaluated. At 2 months after the last dose of Rotarix™, seroconversion rates were identical in the 2-dose (44%; 95% CI = 36–53) and 3-dose (44%; 95% CI = 36–53) vaccine recipients. Although Rotarix™ titres were higher in this latter study [31] compared to the previously described RIX4144 study from the same site [26], the immune responses after the dose 1 at 6 weeks of age and the last dose at 14 weeks of age were quite similar among the respective age groups in both studies. In particular, the immune response among subjects receiving rotavirus vaccine with OPV was substantially lower after dose 1 (13–19%) in both studies compared to the immune response after the last dose at 14 weeks of age (44–46%).