OpenLB
Open Library of Bioscience
Advanced Search
European journal of pediatrics
Mar 05, 2025;184 (3): 229.

Effectiveness of nirsevimab in reducing hospitalizations in emergency departments due to bronchiolitis among infants under 3 months: a retrospective study.

Alexis Marouk, Bernadette Verrat, Isabelle Pontais, Dumitru Cojocaru, H��l��ne Chappuy, Irina Craiu, Pauline Quagliaro, Vincent Gajdos, Val��rie Soussan-Banini, Yves Gallien, Anne-Laure Feral-Pierssens
Author Information
  1. Alexis Marouk: SAMU 93 - SMUR - Emergency Department, Avicenne Hospital, Public Assistance Hospitals Paris, Bobigny, France. alexis.marouk@aphp.fr.
  2. Bernadette Verrat: Data Science Division, Sant�� Publique France, Saint-Maurice, France.
  3. Isabelle Pontais: Data Science Division, Sant�� Publique France, Saint-Maurice, France.
  4. Dumitru Cojocaru: Pediatric Emergency Department, Louis-Mourier Hospital, Public Assistance Hospitals Paris, Colombes, France.
  5. H��l��ne Chappuy: Pediatric Emergency Department, Necker-Enfants Malades Hospital, Public Assistance Hospitals Paris, Paris, France.
  6. Irina Craiu: Pediatric Intensive Care and Neonatal Medicine, Bic��tre Hospital, Public Assistance Hospitals Paris, Le Kremlin-Bic��tre, France.
  7. Pauline Quagliaro: Department of Pediatrics, Jean-Verdier Hospital, Public Assistance Hospitals Paris, Bondy, France.
  8. Vincent Gajdos: Department of Pediatrics, Antoine-B��cl��re Hospital, Public Assistance Hospitals Paris, Clamart, France.
  9. Val��rie Soussan-Banini: Pediatric Emergency Department, Ambroise-Par�� Hospital, Public Assistance Hospitals Paris, Boulogne-Billancourt, France.
  10. Yves Gallien: Data Science Division, Sant�� Publique France, Saint-Maurice, France.
  11. Anne-Laure Feral-Pierssens: SAMU 93 - SMUR - Emergency Department, Avicenne Hospital, Public Assistance Hospitals Paris, Bobigny, France.
PMID: 40044918 DOI: 10.1007/s00431-025-06050-7

Abstract

Respiratory syncytial virus (RSV) is a leading cause of infant morbidity. France has implemented a national campaign using nirsevimab to prevent RSV-related infections in infants. This study assessed its effectiveness in preventing hospitalization due to bronchiolitis in emergency department (ED). This retrospective study was conducted among six pediatric EDs in the Greater Paris area, France, and included infants aged���<���3 months with a clinical diagnosis of bronchiolitis during the 2023-2024 RSV epidemic season. The primary outcome was hospitalization after the ED visits. The association with nirsevimab immunization was assessed using a multiple logistic model adjusted for potential confounding factors, with missing data handled using random forest imputation. Secondary analyses examined the risk of admission to the pediatric intensive care unit (PICU), RSV positivity, and subgroup analyses of prematurity, neonates, and deprivation using the FDep index (area-based measure of social deprivation in France). Between October 2 and December 31, 2023, 739 infants were included in the study. A total of 531 (72%) patients had a documented nirsevimab immunization status, and 402 (54%) were hospitalized following a bronchiolitis diagnosis. Nirsevimab showed 53.5% adjusted effectiveness in reducing hospitalizations (95% CI 34.1-67.3). Sensitivity analyses of complete-case data and propensity score matching yielded similar results. Nirsevimab also resulted in 51.1% reduction in PICU admissions (95% CI 10.7-74.3) and 79.6% reduction in RSV positivity (95% CI 68.0-87.1). The protective effect of immunization was consistent for preterm infants, neonates, and deprived groups, though the results were not statistically significant in these smaller subgroups.
CONCLUSIONS: Immunization with nirsevimab reduced hospitalization following an ED visit for bronchiolitis among infants aged���<���3 months.
WHAT IS KNOWN: ��� Nirsevimab reduces the risk of bronchiolitis-related hospitalizations in clinical trials. ��� Real-world data from the immunization campaign in France remain limited.
WHAT IS NEW: ��� Nirsevimab showed 53.5% (95% CI 34.1-67.3) adjusted effectiveness in reducing hospitalizations for all-cause bronchiolitis in infants aged���<���3 months in emergency departments. ��� Analyses included social deprivation and highlighted potential disparities in immunization access.

Keywords

Bronchiolitis Immunization Nirsevimab Pediatric RSV

References

  1. Ralston SL, Lieberthal AS, Meissner HC, Alverson BK, Baley JE, Gadomski AM et al (2014) Clinical practice guideline: the diagnosis, management, and prevention of bronchiolitis. Pediatrics 134:e1474-1502. https://doi.org/10.1542/peds.2014-2742 [DOI: 10.1542/peds.2014-2742]
  2. Florin TA, Plint AC, Zorc JJ (2017) Viral bronchiolitis. Lancet 389:211���224. https://doi.org/10.1016/S0140-6736(16)30951-5 [DOI: 10.1016/S0140-6736(16)30951-5]
  3. Shi T, McAllister DA, O���Brien KL, Simoes EAF, Madhi SA, Gessner BD et al (2017) Global, regional, and national disease burden estimates of acute lower respiratory infections due to respiratory syncytial virus in young children in 2015: a systematic review and modelling study. Lancet 390:946���958. https://doi.org/10.1016/S0140-6736(17)30938-8 [DOI: 10.1016/S0140-6736(17)30938-8]
  4. Mansbach JM, Piedra PA, Teach SJ, Sullivan AF, Forgey T, Clark S et al (2012) Prospective multicenter study of viral etiology and hospital length of stay in children with severe bronchiolitis. Arch Pediatr Adolesc Med 166:700���706. https://doi.org/10.1001/archpediatrics.2011.1669 [DOI: 10.1001/archpediatrics.2011.1669]
  5. Oakley E, Chong V, Borland M, Neutze J, Phillips N, Krieser D et al (2017) Intensive care unit admissions and ventilation support in infants with bronchiolitis. Emerg Med Australas 29:421���428. https://doi.org/10.1111/1742-6723.12778 [DOI: 10.1111/1742-6723.12778]
  6. Murray J, Bottle A, Sharland M, Modi N, Aylin P, Majeed A et al (2014) Risk factors for hospital admission with RSV bronchiolitis in England: a population-based birth cohort study. PLoS ONE 9:e89186. https://doi.org/10.1371/journal.pone.0089186 [DOI: 10.1371/journal.pone.0089186]
  7. Mansbach JM, McAdam AJ, Clark S, Hain PD, Flood RG, Acholonu U et al (2008) Prospective multicenter study of the viral etiology of bronchiolitis in the emergency department. Acad Emerg Med 15:111���118. https://doi.org/10.1111/j.1553-2712.2007.00034.x [DOI: 10.1111/j.1553-2712.2007.00034.x]
  8. Demont C, Petrica N, Bardoulat I, Duret S, Watier L, Chosidow A et al (2021) Economic and disease burden of RSV-associated hospitalizations in young children in France, from 2010 through 2018. BMC Infect Dis 21:730. https://doi.org/10.1186/s12879-021-06399-8 [DOI: 10.1186/s12879-021-06399-8]
  9. Mahant S, Parkin PC, Thavam T, Imsirovic H, Tuna M, Knight B et al (2022) Rates in bronchiolitis hospitalization, intensive care unit use, mortality, and costs from 2004 to 2018. JAMA Pediatr 176:1���11. https://doi.org/10.1001/jamapediatrics.2021.5177 [DOI: 10.1001/jamapediatrics.2021.5177]
  10. Del Riccio M, Spreeuwenberg P, Osei-Yeboah R, Johannesen CK, Fernandez LV, Teirlinck AC et al (2023) Burden of respiratory syncytial virus in the European Union: estimation of RSV-associated hospitalizations in children under 5 years. J Infect Dis 228:1528���1538. https://doi.org/10.1093/infdis/jiad188 [DOI: 10.1093/infdis/jiad188]
  11. Mesl�� MMI, Sinnathamby M, Mook P, WHO European Region Respiratory Network Group, Pebody R, Lakhani A et al (2023) Seasonal and inter-seasonal RSV activity in the European Region during the COVID-19 pandemic from autumn 2020 to summer 2022. Influenza Other Respir Viruses 17:e13219. https://doi.org/10.1111/irv.13219
  12. Vaux S, Viriot D, Forgeot C, Pontais I, Savitch Y, Barondeau-Leuret A et al (2022) Bronchiolitis epidemics in France during the SARS-CoV-2 pandemic: the 2020���2021 and 2021���2022 seasons. Infectious Diseases Now 52:374���378. https://doi.org/10.1016/j.idnow.2022.06.003 [DOI: 10.1016/j.idnow.2022.06.003]
  13. Project TS (2011) Assessment of syndromic surveillance in Europe. The Lancet 378:1833���1834. https://doi.org/10.1016/S0140-6736(11)60834-9 [DOI: 10.1016/S0140-6736(11)60834-9]
  14. Muller WJ, Madhi SA, Seoane Nu��ez B, Baca Cots M, Bosheva M, Dagan R et al (2023) Nirsevimab for prevention of RSV in term and late-preterm infants. N Engl J Med 388:1533���1534. https://doi.org/10.1056/NEJMc2214773 [DOI: 10.1056/NEJMc2214773]
  15. Drysdale SB, Cathie K, Flamein F, Knuf M, Collins AM, Hill HC et al (2023) Nirsevimab for prevention of hospitalizations due to RSV in infants. N Engl J Med 389:2425���2435. https://doi.org/10.1056/NEJMoa2309189 [DOI: 10.1056/NEJMoa2309189]
  16. Paireau J, Durand C, Raimbault S, Cazaubon J, Mortamet G, Viriot D et al (2024) Nirsevimab effectiveness against cases of respiratory syncytial virus bronchiolitis hospitalised in paediatric intensive care units in France, September 2023���January 2024. Influenza Other Respir Viruses 18:e13311. https://doi.org/10.1111/irv.13311 [DOI: 10.1111/irv.13311]
  17. L��pez-Lacort M, Mu��oz-Quiles C, Mira-Iglesias A, L��pez-Labrador FX, Mengual-Chuli�� B, Fern��ndez-Garc��a C et al (2024) Early estimates of nirsevimab immunoprophylaxis effectiveness against hospital admission for respiratory syncytial virus lower respiratory tract infections in infants, Spain, October 2023 to January 2024. Eurosurveillance 29:2400046. https://doi.org/10.2807/1560-7917.ES.2024.29.6.2400046 [DOI: 10.2807/1560-7917.ES.2024.29.6.2400046]
  18. Cuschieri S (2019) The STROBE guidelines. Saudi J Anaesth 13:S31���S34. https://doi.org/10.4103/sja.SJA_543_18 [DOI: 10.4103/sja.SJA_543_18]
  19. Kaji AH, Schriger D, Green S (2014) Looking through the retrospectoscope: reducing bias in emergency medicine chart review studies. Ann Emerg Med 64:292���298. https://doi.org/10.1016/j.annemergmed.2014.03.025 [DOI: 10.1016/j.annemergmed.2014.03.025]
  20. Pelat C, Bonmarin I, Ruello M, Fouillet A, Caserio-Sch��nemann C, Levy-Bruhl D et al (2017) Improving regional influenza surveillance through a combination of automated outbreak detection methods: the 2015/16 season in France. Euro Surveill 22:30593. https://doi.org/10.2807/1560-7917.ES.2017.22.32.30593 [DOI: 10.2807/1560-7917.ES.2017.22.32.30593]
  21. Schroeder AR, Destino LA, Ip W, Vukin E, Brooks R, Stoddard G et al (2020) Day of illness and outcomes in bronchiolitis hospitalizations. Pediatrics 146:e20201537. https://doi.org/10.1542/peds.2020-1537 [DOI: 10.1542/peds.2020-1537]
  22. Temam S, Varraso R, Pornet C, Sanchez M, Affret A, Jacquemin B et al (2017) Ability of ecological deprivation indices to measure social inequalities in a French cohort. BMC Public Health 17:956. https://doi.org/10.1186/s12889-017-4967-3 [DOI: 10.1186/s12889-017-4967-3]
  23. Pergeline J, Rivi��re S, Rey S, Fresson J, Rachas A, Tuppin P (2023) Social deprivation and the use of healthcare services over one year by children less than 18 years of age in 2018: a French nationwide observational study. PLoS ONE 18:e0285467. https://doi.org/10.1371/journal.pone.0285467 [DOI: 10.1371/journal.pone.0285467]
  24. Jabagi M-J, Cohen J, Bertrand M et al (2024) Rapport d�����tude d���utilisation du Nirs��vimab (Beyfortus��) en ville en France lors de la premi��re campagne de pr��vention (saison 2023/2024). EPI-PHARE. https://www.epi-phare.fr/rapports-detudes-et-publications/utilisation-beyfortus/ . Accessed 12 Sept 2024
  25. Brookhart MA, Schneeweiss S, Rothman KJ, Glynn RJ, Avorn J, St��rmer T (2006) Variable selection for propensity score models. Am J Epidemiol 163:1149���1156. https://doi.org/10.1093/aje/kwj149 [DOI: 10.1093/aje/kwj149]
  26. Austin PC (2011) An introduction to propensity score methods for reducing the effects of confounding in observational studies. Multivariate Behav Res 46:399���424. https://doi.org/10.1080/00273171.2011.568786 [DOI: 10.1080/00273171.2011.568786]
  27. Abadie A, Spiess J (2022) Robust post-matching inference. J Am Stat Assoc 117:983���995. https://doi.org/10.1080/01621459.2020.1840383 [DOI: 10.1080/01621459.2020.1840383]
  28. Carbajal R, Boelle P-Y, Pham A, Chazette Y, Schellenberger M, Weil C et al (2024) Real-world effectiveness of nirsevimab immunisation against bronchiolitis in infants: a case-control study in Paris. France Lancet Child Adolesc Health 8:730���739. https://doi.org/10.1016/S2352-4642(24)00171-8 [DOI: 10.1016/S2352-4642(24)00171-8]
  29. Onwuchekwa C, Moreo LM, Menon S, Machado B, Curcio D, Kalina W et al (2023) Underascertainment of respiratory syncytial virus infection in adults due to diagnostic testing limitations: a systematic literature review and meta-analysis. J Infect Dis 228:173���184. https://doi.org/10.1093/infdis/jiad012 [DOI: 10.1093/infdis/jiad012]
  30. Assad Z, Romain A-S, Aupiais C, Shum M, Schrimpf C, Lorrot M et al (2024) Nirsevimab and hospitalization for RSV bronchiolitis. N Engl J Med 391:144���154. https://doi.org/10.1056/NEJMoa2314885 [DOI: 10.1056/NEJMoa2314885]
  31. Moline HL (2024) Early estimate of nirsevimab effectiveness for prevention of respiratory syncytial virus���associated hospitalization among infants entering their first respiratory syncytial virus season ��� new vaccine surveillance network, October 2023���February 2024. MMWR Morb Mortal Wkly Rep 73. https://doi.org/10.15585/mmwr.mm7309a4 .
  32. Andina Mart��nez D, Claret Teruel G, Gij��n Mediavilla M, C��mara Otegui A, Ba��os L��pez L, de Miguel Lavisier B et al (2024) Nirsevimab and acute bronchiolitis episodes in pediatric emergency departments. Pediatrics e2024066584. https://doi.org/10.1542/peds.2024-066584 .
  33. Curns AT, Rha B, Lively JY, Sahni LC, Englund JA, Weinberg GA et al (2024) Respiratory syncytial virus-associated hospitalizations among children <5 years old: 2016 to 2020. Pediatrics 153:e2023062574. https://doi.org/10.1542/peds.2023-062574 [DOI: 10.1542/peds.2023-062574]
  34. Jones LL, Hashim A, McKeever T, Cook DG, Britton J, Leonardi-Bee J (2011) Parental and household smoking and the increased risk of bronchitis, bronchiolitis and other lower respiratory infections in infancy: systematic review and meta-analysis. Respir Res 12:5. https://doi.org/10.1186/1465-9921-12-5 [DOI: 10.1186/1465-9921-12-5]
  35. Mahant S, Borkhoff CM, Parkin PC, Imsirovic H, Tuna M, Macarthur C et al (2024) Sociodemographic factors and trends in bronchiolitis-related emergency department visit and hospitalization rates. JAMA Netw Open 7:e248976. https://doi.org/10.1001/jamanetworkopen.2024.8976 [DOI: 10.1001/jamanetworkopen.2024.8976]
  36. Chung A, Reeves RM, Nair H, Campbell H (2020) RESCEU investigators. Hospital admission trends for bronchiolitis in Scotland, 2001-2016: a national retrospective observational study. J Infect Dis 222:592���8. https://doi.org/10.1093/infdis/jiaa323 [DOI: 10.1093/infdis/jiaa323]
  37. Kampmann B, Madhi SA, Munjal I, Sim��es EAF, Pahud BA, Llapur C et al (2023) Bivalent prefusion F vaccine in pregnancy to prevent RSV illness in infants. N Engl J Med 388:1451���1464. https://doi.org/10.1056/NEJMoa2216480 [DOI: 10.1056/NEJMoa2216480]
  38. Lassoued Y, Levy C, Werner A, Assad Z, Bechet S, Frandji B et al (2024) Effectiveness of nirsevimab against RSV-bronchiolitis in paediatric ambulatory care: a test-negative case���control study. Lancet Regional Health - Europe 44:101007. https://doi.org/10.1016/j.lanepe.2024.101007 [DOI: 10.1016/j.lanepe.2024.101007]
  39. Ravi N, Gitz KM, Burton DR, Ray KN (2021) Pediatric non-urgent emergency department visits and prior care-seeking at primary care. BMC Health Serv Res 21:466. https://doi.org/10.1186/s12913-021-06480-7 [DOI: 10.1186/s12913-021-06480-7]

MeSH Term

Humans
Retrospective Studies
Infant
Emergency Service, Hospital
Hospitalization
Male
Female
Respiratory Syncytial Virus Infections
Infant, Newborn
Antiviral Agents
Bronchiolitis
France

Chemicals

Antiviral Agents
Journal Article Multicenter Study
Article has an altmetric score of 15

Word Cloud

Created with Highcharts 10.0.0infantsbronchiolitisRSVnirsevimabimmunizationNirsevimabFranceusingstudyhospitalizations95%CI���effectivenesshospitalizationemergencyEDamongincludedadjusteddataanalysesdeprivationreducing3campaignassesseddueretrospectivepediatricaged���<���3 monthsclinicaldiagnosispotentialriskPICUpositivityneonatessocialfollowingshowed535%341-67resultsreductionImmunizationWHATISdepartmentsRespiratorysyncytialvirusleadingcauseinfantmorbidityimplementednationalpreventRSV-relatedinfectionspreventingdepartmentconductedsixEDsGreaterParisarea2023-2024epidemicseasonprimaryoutcomevisitsassociationmultiplelogisticmodelconfoundingfactorsmissinghandledrandomforestimputationSecondaryexaminedadmissionintensivecareunitsubgroupprematurityFDepindexarea-basedmeasureOctober2December312023739total53172%patientsdocumentedstatus40254%hospitalizedSensitivitycomplete-casepropensityscorematchingyieldedsimilaralsoresulted511%admissions107-74796%680-871protectiveeffectconsistentpretermdeprivedgroupsthoughstatisticallysignificantsmallersubgroupsCONCLUSIONS:reducedvisitaged���<���3monthsKNOWN:reducesbronchiolitis-relatedtrialsReal-worldremainlimitedNEW:all-causeAnalyseshighlighteddisparitiesaccessEffectiveness3 months:BronchiolitisPediatric

Similar Articles

Cited By