Comparison of 2 different regimens for reactogenicity, safety, and immunogenicity of the live attenuated oral rotavirus vaccine RIX4414 coadministered with oral polio vaccine in South African infants.

BACKGROUND: A phase II, randomized, double-blind, placebo-controlled study was conducted in South Africa during 2003-2004 to evaluate the safety, reactogenicity, and immunogenicity of 2 regimens of the live attenuated oral human rotavirus vaccine RIX4414 when coadministered with the Expanded Program on Immunization childhood vaccines, including oral polio vaccine. METHODS: Healthy infants were randomized (2:2:1) to receive either 2 doses of RIX4414 (n = 190; at 10 and 14 weeks, with placebo at 6 weeks), 3 doses of RIX4414 (n = 189; at 6, 10, and 14 weeks), or 3 doses of placebo (n = 96), all with concomitant routine vaccinations. The antirotavirus IgA seroconversion rate was assessed using enzyme-linked immunosorbent assay at 2 months after the last dose of RIX4414 or placebo. Antipolio types 1, 2, and 3 antibodies were measured using a virus neutralization assay. Solicited symptoms were recorded for 15 days after each dose. RESULTS: The antirotavirus IgA seroconversion rates were similar in the RIX4414 2- and 3-dose groups (44.3% and 44.4%, respectively; P = .544, by 1-sided Fisher exact test) and antirotavirus IgA geometric mean concentrations were also comparable. Seroprotection rates for antipolio types 1, 2, and 3 antibodies were high (93%-100%) and were not significantly different among groups. Solicited symptoms reported within 15 days after vaccination were similar in all groups. CONCLUSIONS: The immune seroconversion response to the RIX4414 vaccine with 3 doses was not superior to the 2-dose regimen. There was no interference by either regimen with antibody response to oral polio vaccine, and RIX4414 was well tolerated when given with routine vaccinations.

Co-administration study in South African infants of a live-attenuated oral human rotavirus vaccine (RIX4414) and poliovirus vaccines.

A double-blind, placebo-controlled phase II trial (e-Track 444563-014/NCT00346892) was conducted in South Africa to evaluate the co-administration of RIX4414 (live-attenuated human G1P[8] rotavirus vaccine) and oral poliovirus vaccine (OPV) administered simultaneously. Healthy infants (n=450) were randomized into three groups (RIX4414+OPV, RIX4414+IPV or Placebo+OPV) to receive two oral doses of RIX4414/placebo with OPV or IPV using two vaccination schedules (6-10 weeks and 10-14 weeks). Serum anti-rotavirus IgA antibodies (ELISA) and neutralizing antibodies (micro-neutralization assay) to poliovirus serotypes 1, 2 and 3 were measured. Co-administration of RIX4414 with OPV did not result in a decrease in the high sero-protection rates against poliovirus serotypes 1, 2 and 3 detected after the third OPV dose (98-100%). The anti-rotavirus IgA antibody sero-conversion rates were higher for the 10-14 weeks schedule (55-61%) compared to the 6-10 weeks schedule (36-43%). Solicited symptoms were reported at similar rates between RIX4414 and placebo groups and no serious adverse events related to RIX4414 were reported. This study provided evidence that RIX4414 can be co-administered with routine EPI immunizations including OPV and that two doses of RIX4414 were well tolerated and immunogenic in South African infants.

Nonperturbative flow equations from running expectation values.

We show that Wegner's flow equations, as recently discussed in the Lipkin model, can be solved self-consistently. This leads to a nonlinear differential equation which fully determines the order parameter as a function of the dimensionless coupling constant, even across the phase transition. Since we consider an expansion in the fluctuations, rather than the conventional expansion in the coupling constant, convergence to the exact results is found in both phases when taking the thermodynamic limit.