RSV vaccine during pregnancy or nirsevimab for infants: Which works better?

Clinical takeaway: Counsel expectant parents that either maternal RSV vaccination during late pregnancy or infant nirsevimab appears to provide comparable protection against RSV during the first 6 months of life, supporting current recommendations that families can choose based on preference and availability.

Since 2023, clinicians have had two effective strategies to prevent severe infant RSV disease: maternal vaccination with RSVpreF during pregnancy or infant immunization with nirsevimab after birth. Until now, real-world head-to-head comparisons have been limited, leaving uncertainty about whether one approach offers superior protection.

In this retrospective cohort study from Kaiser Permanente Northern California, investigators analyzed matched data from 15,124 full-term infants born during the 2023-2024 and 2024-2025 RSV seasons who received either maternal RSVpreF protection or nirsevimab.

RSV infection rates were nearly identical. PCR-confirmed RSV occurred in 0.94% of infants whose mothers received RSVpreF and 1.04% of infants given nirsevimab. RSV hospitalization was also uncommon, affecting 0.06% and 0.13% of infants, respectively. The differences were not statistically significant, and results were similar when researchers examined only the 2024-2025 season or limited follow-up to the first 90 days of life.

When compared with infants who received neither intervention, both strategies were strongly protective. Maternal RSVpreF was associated with roughly 69% fewer RSV infections and 86% fewer RSV hospitalizations. Nirsevimab was associated with about 65% fewer infections and 74% fewer hospitalizations. Among infants who developed breakthrough RSV infections despite protection, hospitalization rates remained low and did not differ significantly between groups.

The authors concluded: “Physicians and expectant parents may continue to choose which protection method to receive based on personal preference or local availability.”

Source: Jacobson KB, et al. (2026 Oct 24) JAMA Netw Open. Maternal Vaccination vs Nirsevimab Use and Respiratory Syncytial Virus Infection Among Full-Term Infants