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Assessing Respiratory Immune Responses to Haemophilus Influenzae
Published on: June 29, 2021
Effectiveness of nirsevimab immunisation on invasive pneumococcal disease in children nationwide in France: an
Inès Fafi1, Zaba Valtuille2, Florentia Kaguelidou3
1Université Paris Cité and Université Sorbonne Paris Nord, Inserm, IAME UMR 1137, Paris, France; Clinical Investigation Centre, Inserm CIC1426, Robert Debré University Hospital, Assistance Publique-Hôpitaux de Paris, Paris, France; Department of General Paediatrics, Paediatric Infectious Disease and Internal Medicine, Robert Debré University Hospital, Assistance Publique-Hôpitaux de Paris, Paris, France.
Insights
Nirsevimab immunisation in infants significantly reduced the risk of invasive pneumococcal diseases (IPD). This monoclonal antibody offers protection beyond preventing RSV disease, suggesting broader public health benefits.
Area of Science:
- Pediatrics
- Immunology
- Infectious Diseases
Background:
- Invasive pneumococcal diseases (IPDs) cause significant global child morbidity and mortality.
- Respiratory syncytial virus (RSV) infection is linked to increased IPD risk.
- Pneumococcal conjugate vaccines have limitations in preventing IPD.
Purpose of the Study:
- To assess if nirsevimab, an RSV monoclonal antibody, reduces IPD risk in children.
- To evaluate the effectiveness of nirsevimab beyond its primary indication.
Main Methods:
- Population-based retrospective cohort study in France.
- Included liveborn infants (Feb 2023–Jan 2024) with nirsevimab status.
- Propensity score analysis (IPTW) compared nirsevimab-immunised vs. non-immunised infants.
- Primary outcome: IPD hospitalisation within 6 months post-immunisation.
Main Results:
- 527,971 infants included; 22.6% received nirsevimab.
- Nirsevimab associated with a 36% reduction in IPD hospitalisation odds at 6 months.
- Effectiveness sustained at 34% reduction at 9 months post-immunisation.
Conclusions:
- Nirsevimab immunisation in infants (<12 months) lowers IPD risk for at least 6 months.
- Suggests nirsevimab provides benefits beyond RSV prevention.
- Further studies are needed to confirm these findings.
Background:
Invasive pneumococcal diseases (IPDs) remain a leading cause of morbidity and mortality in children worldwide, despite the widespread use of pneumococcal conjugate vaccines. Respiratory syncytial virus (RSV) disease is suspected to be associated with an increased risk of IPD. We assessed whether immunisation with nirsevimab, a monoclonal antibody targeting RSV, reduced the risk of IPD in children.
Methods:
This population-based, retrospective cohort study used data from the French National Health Data System. All liveborn children in metropolitan France between Feb 6, 2023, and Jan 31, 2024, for whom nirsevimab immunisation status was available, were included. The date of nirsevimab immunisation defined the inclusion date of immunised children and their birth-month-matched non-immunised children. Children immunised with nirsevimab during the first year of life constituted the immunised group, whereas children non-immunised with nirsevimab constituted the non-immunised group. The primary outcome was hospitalisation for IPD within 6 months after inclusion. Propensity score analysis using inverse probability of treatment weighting (IPTW) was conducted to adjust for differences in baseline characteristics between the two groups. Immunisation effectiveness was calculated with the use of the following equation: effectiveness=100% × (1 - odds ratio [OR]), with the OR reflecting the association between nirsevimab and IPD.
Findings:
Of the 608 641 children born in France during the study period, 527 971 were included, of whom 119 435 (22·6%) received nirsevimab. During the 6-month follow-up period, 112 cases of IPD occurred: 17 (14·2 per 100 000) in the immunised group versus 95 (23·3 per 100 000) in the non-immunised group. After IPTW, nirsevimab was associated with a 36% reduction in the odds of hospitalisation for IPD 6 months after immunisation (OR 0·64, 95% CI 0·46-0·82). 9 months after immunisation, effectiveness remained consistent with a 34% reduction (0·66, 0·51-0·85).
Interpretation:
Nirsevimab immunisation in children younger than 12 months was associated with a lower risk of IPD for at least 6 months following immunisation. These findings suggest an additional benefit of nirsevimab implementation beyond RSV disease prevention, but further studies are needed to confirm these findings.
Funding:
AP-HP Research fellowship, ATIP-Avenir partnership, and AP-HP Foundation.
Translations:
For the French translation of the abstract see Supplementary Materials section.
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