Jan 13, 2026
3 min read
Children who received nirsevimab had a greater risk of hospitalization for RSV-related lower respiratory infections than children protected by maternal RSV vaccination.
During the first respiratory syncytial virus (RSV) season in France, passive immunization of infants with nirsevimab was associated with a lower risk of hospitalization for RSV-related lower respiratory tract infection and other severe outcomes than maternal vaccination with RSV F protein prefusion (RSVpreF).
- Researchers in France conducted a population-based study to compare the associations of maternal RSVpreF vaccination and passive infant immunization with nirsevimab to prevent infant RSV-related hospitalizations during the 2024-2025 RSV season.
- A total of 21,280 infants born to RSVpreF-vaccinated mothers at 32-36 weeks' gestation (median age at discharge, 3.8 days, 51.7% male) were matched to a similar number of infants who received nirsevimab based on maternal date, sex, and due date.
- The primary outcome was hospitalization for RSV-related lower respiratory tract infections;Secondary outcomes included admission to a pediatric ICU or high-dependency unit, respiratory support, and supplemental oxygen therapy.
- The mean duration of follow-up was 84 days, starting from the day of discharge from the maternity hospital.
- A total of 481 hospitalizations for RSV-related lower respiratory tract infections occurred, with 44.1% in the nirsevimab group versus 55.9% in the RSVpreF vaccination group (intermediate group, -11.8%; 95% CI, -18.5% to -5.5%).
- Passive immunization of infants with nirsevimab was associated with a 26% lower risk of hospitalization for RSV-associated lower respiratory tract infection compared with maternal RSVpreF vaccination (adjusted hazard ratio [aHR], 0.74; 95% CI, 0.61-0.88).
- Compared with maternal RSVPref vaccination, passive infant vaccination with nirsevimab was associated with a reduced risk of pediatric ICU admission (aHR, 0.58; 95% CI, 0.42-0.80);however, there was no significant difference in high dependency unit admission (aHR, 0.87; 95% CI, 0.60-1.25).
- Rates of hospitalization requiring ventilator support and oxygen therapy were also reduced in the nirsevimab group.
"This study compared the results of passive immunization with NIRSevimab versus RSVPREF vaccination, and its results should not be interpreted as evidence against the efficacy of RSVPREF vaccination," the authors wrote.
The study was led by Marie-Joelle Jabagi, PharmD, PhD, French Agency for the Safety of Medicines and Food and French National Health Insurance, Paris, France.It was published online December 22, 2025 in JAMA.
This study only covered one season of RSV.Therefore, it could not evaluate the durability of the protection.Because the vaccine was released in September and matching was based on birth dates, children born earlier in the RSV season may be underrepresented, which may have limited generalizability.The analysis reflected the first maternal vaccination period in France, limited to 32-36 weeks of gestation.However, the guidelines recommend vaccination starting from the 28th week of pregnancy.
This study was funded by the French National Agency for Medicines and Health Products Safety and the French National Health Insurance.The authors report no relevant conflicts of interest.
This article was created using various editorial tools, including AI, as part of the process.Editors reviewed this content before publication.
