Remote Recruitment to Diversify Infant Research Participation: Lessons From the Infant Vaccine Biepository.

AIM: To determine whether remote recruitment, electronic consent and at-home blood collection enabled enrollment of a geographically and socioeconomically diverse infant cohort in the United States (US). METHODS: We describe the demographics of 256 infants included in this analysis, drawn from 264 enrolled in the Infant Vaccine Biorepository (December 2022-April 2026). Participants were recruited via online advertising and electronic medical record messaging. Geographic distribution was assessed using US Census regions and Rural-Urban Commuting Area (RUCA) codes. Social vulnerability was characterized using the Centers for Disease Control and Prevention (CDC) Social Vulnerability Index (SVI) at census tract and county levels, with nationwide rankings. RESULTS: Infants were distributed evenly across the four US geographic regions; 9% resided in rural areas. Based on nationwide census tract-level SVI rankings, 39.8% of participants fell in the medium-high or high vulnerability categories. County-level SVI rankings indicated that 57.0% of participants fell in these same categories. Participants were 78% White and 20% Hispanic; 94.1% of mothers had received at least one COVID-19 vaccine. CONCLUSION: Fully remote recruitment, consent and specimen collection enabled enrollment of infants from diverse geographic and socioeconomic backgrounds across the US. SVI and RUCA provide richer characterization of study populations than traditional demographic measures alone.