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Multicenter Study
. 2025 Feb 1;179(2):179-187.
doi: 10.1001/jamapediatrics.2024.5572.

Respiratory Syncytial Virus Disease Burden and Nirsevimab Effectiveness in Young Children From 2023-2024

Heidi L Moline  1   2 , Ariana P Toepfer  1 , Ayzsa Tannis  1 , Geoffrey A Weinberg  3 , Mary A Staat  4   5 , Natasha B Halasa  6 , Julie A Boom  7   8 , Eileen J Klein  9 , John V Williams  10   11 , Jennifer E Schuster  12 , Leah Goldstein  1 , Erin R McKeever  1 , Casey Kalman  1 , Clinton Paden  1 , Lydia Atherton  1 , Megha Aggarwal  1 , Pavitra Roychoudhury  13 , Pedro A Piedra  7   8   14 , Leila C Sahni  7   8 , Laura S Stewart  6 , Rangaraj Selvarangan  15 , Marian G Michaels  10 , Elizabeth P Schlaudecker  4   5 , Peter G Szilagyi  3   16 , Janet A Englund  9 , Benjamin R Clopper  1 , Natalie J Thornburg  1 , Gordana Derado  1 , Meredith L McMorrow  1   2 , Fatimah S Dawood  1   2 ; New Vaccine Surveillance Network Collaborators
Collaborators, Affiliations
Multicenter Study

Respiratory Syncytial Virus Disease Burden and Nirsevimab Effectiveness in Young Children From 2023-2024

Heidi L Moline et al. JAMA Pediatr. .

Erratum in

Abstract

Importance: During the 2023-2024 respiratory syncytial virus (RSV) season in the United States, 2 new RSV prevention products were recommended to protect infants in their first RSV season: nirsevimab and Pfizer's maternal RSV vaccine. Postlicensure studies are needed to assess prevention product impact and effectiveness.

Objective: To compare the epidemiology and disease burden of medically attended RSV-associated acute respiratory illness (ARI) among children younger than 5 years during the 2023-2024 RSV season with 3 prepandemic RSV seasons (2017-2020), estimate nirsevimab effectiveness against medically attended RSV-associated ARI, and compare nirsevimab binding site mutations among circulating RSV in infants with and without nirsevimab receipt.

Design, setting, and participants: This study included prospective population-based surveillance for medically attended ARI with systematic molecular testing for RSV and whole-genome sequencing of RSV positive samples, as well as a test-negative case-control design to estimate nirsevimab effectiveness. The study was conducted in 7 academic pediatric medical centers in the United States with data from RSV seasons (September 1 through April 30) in 2017 through 2020. Participants were children younger than 5 years with medically attended ARI.

Exposure: For the nirsevimab effectiveness analyses, nirsevimab receipt among infants younger than 8 months as of or born after October 1, 2023.

Main outcome and measure: Medically attended RSV-associated ARI.

Results: Overall, 28 689 children younger than 5 years with medically attended ARI were enrolled, including 9536 during September 1, 2023, through April 30, 2024, and 19 153 during the same calendar period of 2017-2020. Of these children, 16 196 (57%) were male, and 12 444 (43.4) were female; the median (IQR) age was 15 (6-29) months. During 2023-2024, the proportion of children with RSV was 23% (2199/9490) among all medically attended episodes, similar to 2017-2020. RSV-associated hospitalization rates in 2023-2024 were similar to average 2017-2020 seasonal rates with 5.0 (95% CI, 4.6-5.3) per 1000 among children younger than 5 years; the highest rates were among children aged 0 to 2 months (26.6; 95% CI, 23.0-30.2). Low maternal RSV vaccine uptake precluded assessment of effectiveness. Overall, 10 of 765 case patients (1%) who were RSV positive and 126 of 851 control patients (15%) who were RSV negative received nirsevimab. Nirsevimab effectiveness was 89% (95% CI, 79%-94%) against medically attended RSV-associated ARI and 93% (95% CI, 82%-97%) against RSV-associated hospitalization. Among 229 sequenced specimens, there were no differences in nirsevimab binding site mutations by infant nirsevimab receipt status.

Conclusions and relevance: This analysis documented the continued high burden of medically attended RSV-associated ARI among young children in the US. There is a potential for substantial public health impact with increased and equitable prevention product coverage in future seasons.

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Conflict of interest statement

Conflict of Interest Disclosures: Dr Weinberg reported grants from the New York State Department of Health and consultant, scientific advisory or data and safety board, and/or textbook chapter honoraria from the New York State Department of Health, Inhalon Biopharma, Merck, Emory University, and ReViral outside the submitted work. Dr Staat reported grants from the National Institutes of Health (NIH), Pfizer, Cepheid, and Merck outside the submitted work. Dr Halasa reported grants from Sanofi, Quidel, and Merck outside the submitted work. Dr. Williams reported scientific advisory board fees from Quidel and independent data monitoring committee fees from GlaxoSmithKline outside the submitted work. Dr Schuster reported grants paid to their institution from the National Institutes of Health consultant fees from the Association of American Medical Colleges outside the submitted work. Dr Piedra reported grants from Novavax, Janssen, and Icosavax and data and safety monitoring board fees from Sanofi Pasteur outside the submitted work. Dr Sahni reported travel support from the Gates Foundation outside the submitted work. Dr Selvarangan reported grants from Biomerieux, Hologic, Abbott, Qiagen, Merck, and Cepheid and advisory board fees from GlaxoSmithKline outside the submitted work. Dr Michaels reported grants paid to their institution from the NIH and Merck and nonfinancial support from Viracor outside the submitted work. Dr Schlaudecker reported grants from Pfizer and advisory committee fees from Sanofi Pasteur outside the submitted work. Dr Szilagyi reported grants from the University of California, Los Angeles, during the conduct of the study. Dr Englund reported grants from AstraZeneca, GlaxoSmithKline, Pfizer, and Moderna and personal fees from AbbVie, AstraZeneca, Ark Biopharma, GlaxoSmithKline, Merck, Meissa, Moderna, Pfizer, Shinogi, and Sanofi Pasteur outside the submitted work. No other disclosures were reported.

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References

    1. Hansen CL, Chaves SS, Demont C, Viboud C. Mortality associated with influenza and respiratory syncytial virus in the US, 1999-2018. JAMA Netw Open. 2022;5(2):e220527-e220527. doi:10.1001/jamanetworkopen.2022.0527 - DOI - PMC - PubMed
    1. Hall CB, Weinberg GA, Iwane MK, et al. . The burden of respiratory syncytial virus infection in young children. N Engl J Med. 2009;360(6):588-598. doi:10.1056/NEJMoa0804877 - DOI - PMC - PubMed
    1. McLaughlin JM, Khan F, Schmitt HJ, et al. . Respiratory syncytial virus-associated hospitalization rates among US infants: a systematic review and meta-analysis. J Infect Dis. 2022;225(6):1100-1111. doi:10.1093/infdis/jiaa752 - DOI - PMC - PubMed
    1. Suh M, Movva N, Jiang X, et al. . Respiratory syncytial virus is the leading cause of United States infant hospitalizations, 2009-2019: a study of the National (Nationwide) Inpatient Sample. J Infect Dis. 2022;226(suppl 2):S154-S163. doi:10.1093/infdis/jiac120 - DOI - PMC - PubMed
    1. Curns AT, Rha B, Lively JY, et al. . Respiratory syncytial virus-associated hospitalizations among children <5 years old: 2016 to 2020. Pediatrics. 2024;153(3):e2023062574. doi:10.1542/peds.2023-062574 - DOI - PubMed

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