2280. Antibiotic Exposure Does Not Impact Serological Responses to Rotavirus Vaccination

BACKGROUND: Antibiotic exposure around the time of rotavirus (RV) immunization has been suggested to diminish immune responses, but data are sparse. METHODS: We retrospectively analyzed data from a randomized RV vaccine study (NCT01266850) outlined in the Table. Concomitant antibiotic use, defined as receipt of an antibiotic 14 days before or 7 days after RV immunization, was recorded. The primary outcome was RV-specific IgA seroresponse (IgA ≥20 U/mL) by ELISA obtained 1 month after the last dose of RV vaccine and geometric mean titer (GMT) to strain WC3 (RV5 backbone) or strain 89–12 (RV1 backbone). Only subjects who received all scheduled vaccine doses and phlebotomy were included. Data were assessed for homogeneity across vaccine schedule groups, stratified by antibiotic exposure. We examined differences in seroresponse adjusting for treatment group, gender, race, ethnicity, and study site using logistic regression models. RESULTS: Of the 1384 immunized children, 1174 (85%) met inclusion criteria. Nearly 10% (n = 114) of participants were antibiotic exposed; group 4 had the least antibiotic exposure (P = 0.05). No differences in GMT or seroresponses were observed to either WC3 or 89–12 (figure) by antibiotic exposure. In the multivariable logistic regression model, there were no significant differences for gender, race, ethnicity, site, or antibiotic exposure (P-value ≥0.5 for IgA seroresponse). The only observed difference in seroresponses was by RV vaccine group (P < 0.0001). CONCLUSION: Antibiotic administration around the time of RV vaccine did not diminish RV-specific IgA seroresponses observed 1 month after the last RV vaccine dose. DISCLOSURES: E. J. Anderson, NovaVax: Grant Investigator, Research grant. Pfizer: Grant Investigator, Research grant. AbbVie: Consultant, Consulting fee. MedImmune: Investigator, Research support. PaxVax: Investigator, Research support. Micron: Investigator, Research support. C. B. Creech, Pfizer: Grant Investigator, Research grant. Novartis: Grant Investigator, Research grant. A. L. Shane, International Scientific Association of Probiotics and Prebiotics: Member, Reimbursement of travel and lodging for attendance and presentations at international scientific meetings 2016 and prior and support for attendance at meeting at FDA in 2017 to discuss probiotic and prebiotic research. K. Edwards, Novartis: Grant Investigator, Research grant. Novartis: Scientific Advisor, Consulting fee.