Nirsevimab Linked to Lower Infant Hospitalization Risk Than Maternal Vaccine

First real-world comparison shows lower hospitalization and severe illness rates with infant immunization vs maternal vaccination.

By
Andrea Surnit
April 24, 2026
3 min

Conexiant

Overview

A nationwide French cohort study found that infants receiving nirsevimab shortly after birth had a 26% lower risk of hospitalization for RSV-associated lower respiratory tract infection compared to infants protected via maternal RSVpreF vaccination during pregnancy. Nirsevimab was also linked to fewer severe outcomes such as PICU admission and ventilatory support.

Background

Respiratory syncytial virus (RSV) is a leading cause of lower respiratory tract infections and hospitalization in infants. Preventive strategies include maternal vaccination during pregnancy and direct infant immunization with monoclonal antibodies like nirsevimab. While both approaches have shown efficacy in clinical trials, direct real-world comparisons during the same RSV season have been limited. This study aimed to evaluate the comparative effectiveness of these two strategies in reducing RSV-related hospitalizations and severe outcomes in early infancy.

Data Highlights

Outcome	Nirsevimab Group (n=?)	Maternal Vaccination Group (n=?)
RSV-associated hospitalizations	212 (44%)	269 (56%)
Relative reduction in hospitalization risk	26% lower with nirsevimab
Severe outcomes (PICU admission, ventilatory support, oxygen therapy)	Less prevalent	More prevalent

Key Findings

Infants receiving nirsevimab had a 26% lower likelihood of hospitalization for RSV-associated lower respiratory tract infection compared to those with maternal RSVpreF vaccination.
Severe RSV-related outcomes, including PICU admission, ventilatory support, and oxygen therapy, were less common in the nirsevimab group.
Subgroup analyses showed consistent benefits of nirsevimab across sex, gestational age, and socioeconomic status.
The relative benefit of nirsevimab increased over time, with lower hospitalization risk observed after 30 days and continuing beyond 60 days post-discharge.
Hospitalization risk was higher in the nirsevimab group during the first week after discharge, likely due to differences in timing of protection onset between the two strategies.
Both strategies reduced adverse RSV-related outcomes, but nirsevimab demonstrated superior effectiveness during early infancy in this real-world setting.

Clinical Implications

Clinicians should consider nirsevimab as a potentially more effective option for preventing RSV-related hospitalizations and severe outcomes in infants compared to maternal RSVpreF vaccination. The timing of protection onset differs between strategies, which may influence early post-discharge risk. Ongoing evaluation and individualized decision-making are warranted as both approaches are implemented in clinical practice.

Conclusion

This large real-world study suggests that infant immunization with nirsevimab provides greater protection against RSV hospitalization and severe disease than maternal vaccination during pregnancy. Future research should continue to assess these strategies across diverse populations and seasons.