Comparison of immunogenicity and efficacy of rhesus rotavirus reassortant vaccines in breastfed and nonbreastfed XXXX . US Rotavirus Vaccine Efficacy Group.

@entity1 @entity27320
OBJECTIVE: To evaluate whether breastfeeding affected the immunogenicity and/or efficacy of candidate rhesus- @entity1 rotavirus reassortant vaccines. METHODS: A total of 989 healthy @entity1 between 4 and 26 weeks of age were enrolled into a 23-center, prospective, randomized, double-masked, controlled study of the safety, immunogenicity, and efficacy of three doses (4 x 10(4) plaque-forming units) of monovalent rhesus- @entity1 viral protein 7, or G, serotype 1 reassortant vaccine, ( @entity27320 -S1) or tetravalent vaccine ( @entity27320 -TV) consisting of rhesus- @entity1 reassortant G serotypes 1, 2, and 4, and the parent @entity27320 G serotype 3. Vaccine efficacy was compared in the breastfed and nonbreastfed @entity1 as well as seroconversion rates and postvaccination geometric mean titers (GMTs) of neutralizing antibodies to @entity1 serotypes 1, 2, 3, and 4, @entity27320 , and immunoglobulin A to @entity27320 . GMTs in the two feeding groups were compared with and without adjustment for age at initiation of vaccination, prevaccination antibody titers, and the age and prevaccination titer interaction. RESULTS: The seroconversion rates to both vaccines by one or more assays were similar for the breastfed and the nonbreastfed groups ( @entity27320 -S1, 84% and 85%, respectively; @entity27320 -TV, 94% and 93%, respectively). There were no significant differences in postvaccination GMTs to either vaccine, measured by any serologic assay, in the two feeding groups. The efficacy of the @entity27320 -S1 vaccine was not significantly lower among the breastfed @entity1 than the nonbreastfed @entity1 (28% and 39%, respectively). @entity27320 -TV, which is the vaccine being further evaluated for licensure, was equally protective in breastfed and nonbreastfed @entity1 (50% and 51%, respectively). Logistic regression analysis, taking into account differences in age at vaccination and day 1 titer, revealed no evidence of differential vaccine efficacy in the two feeding groups for either vaccine. CONCLUSIONS: These results indicate that the @entity27320 -TV vaccine, given as three doses of 4 x 10(4) plaque-forming units, induces similar seroresponses and protection in breastfed and nonbreastfed US @entity1 .
