1145. The Role of Maternal Vaccination on Healthcare Visits for Acute Respiratory Infections in HIV-Exposed but Uninfected (HEU) Infants

BACKGROUND: HEU infants remain at higher risk for hospitalization and severe infection from common childhood illnesses. Maternal immunization during pregnancy with influenza and tetanus, diphtheria, pertussis (Tdap) vaccine is recommended and effective at protecting infants from vaccine-preventable infections. METHODS: We conducted a retrospective cohort study of pregnant women living with HIV (WLWH) who delivered and received prenatal care at Grady Memorial Hospital (GMH) between November 1, 2012 and June 30, 2018. Vaccination history was ascertained through the Georgia Registry of Immunization Transactions and Services or by review of electronic medical record. Mother and infant charts were reviewed. We defined acute respiratory infection (ARI) as infants who presented with symptoms or an admitting diagnosis suggestive of an ARI. Relative risks (RR) of identified care visits (clinic, ED/urgent care, hospitalization) in the 6 months post-partum between WLWH with varying vaccinations were compared with 95% confidence intervals. RESULTS: 236 WLWH who delivered at GMH were identified (Table 1). Of those, 66 (28%) received only influenza, 32 (14%) received only Tdap vaccine, 64 (27%) received both and 74 (31%) did not receive any vaccines during pregnancy. There was a trend towards decreased risk of a clinic visit, emergency department/urgent care visit, or any healthcare-associated visit in the first 6 months of life for an ARI in infants born to mothers who received any vaccine during pregnancy versus none although not reaching statistical significance (Table 2). There was a trend towards decreased risk of hospitalization for an ARI in the first six months of life in infants born to mothers who received both influenza and Tdap vaccines during pregnancy versus unvaccinated (RR 0.55, 95%CI: 0.14-2.22). Infants born to mothers vaccinated tended to have higher gestational age than those that did not (Table 3). Table 1. Demographic and Characteristics of Mothers [Image: see text] Table 2. Relative Risk of a Healthcare Visit in the first 6 months of life for URI in Vaccinated vs Unvaccinated Mothers [Image: see text] Table 3. Birth outcomes in HEU infants of Vaccinated vs Unvaccinated Mothers [Image: see text] CONCLUSION: There was a lower risk of healthcare visits for ARI in the first 6-months of life in HEU infants born to mothers who received antepartum vaccinations. Although not statistically significant, larger studies are needed to fully characterize the immune responses in this unique population. DISCLOSURES: All Authors: No reported disclosures