Uptake of the RSVpreF vaccine during pregnancy: associations with socioeconomic status, prenatal care utilization, and maternal risk factors.

Respiratory syncytial virus (RSV) is a leading cause of infant respiratory illness. In August 2023, the RSV protein-based vaccine (RSVpreF) became the first maternal vaccine approved in the United States to prevent RSV infection in newborns. The study aims to estimate RSVpreF vaccine uptake during its first RSV season and to identify key factors associated with uptake among commercially insured pregnant individuals, using Optum's Clinformatics® Data Mart Database. The study included individuals aged 18-50 with live birth deliveries at or after 32 weeks' gestation between October 1, 2023, and January 31, 2024, continuous enrollment from July 1, 2022, through delivery, and available socioeconomic records. Among 14,121 pregnant individuals,14.5% received the RSVpreF vaccine. Uptake rose from 1.5% among the October 2023 delivery cohort to 28.7% among the January 2024 cohort; 84.6% were vaccinated within the recommended 32-36 week gestational window. In multivariable models, higher uptake was associated with age (30-39 vs 18-29 years: OR = 1.52, 95% CI: 1.28-1.80), household income $60,000-$74,000 (OR = 1.40, 95% CI: 1.05-1.85) or $75,000-$99,000 (OR = 1.47, 95% CI: 1.13-1.92), bachelor's degree or higher (OR = 1.70, 95% CI: 1.48-1.96), PPO insurance (OR = 2.87, 95% CI: 1.70-4.87), prior influenza vaccination (OR = 1.78, 95% CI: 1.56-2.04), receipt of influenza (OR = 3.65, 95% CI: 3.14-4.24) or Tdap (OR = 4.40, 95% CI: 3.53-5.49) vaccines during pregnancy, and each additional week in the RSVpreF vaccination window(OR = 1.27; 95% CI: 1.06-1.53). Receiving ≥5 of 7 non-vaccine prenatal care services was also associated with higher uptake (OR = 1.82, 95% CI: 1.23-2.70). Comorbidities were not associated with uptake. Maternal RSVpreF vaccine uptake was low during its first on-market season, with significant disparities by sociodemographic factors, uptake of other vaccines, and adherence to recommended prenatal care. Efforts to improve equitable access and education are needed for effective maternal immunization programs.