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Multicenter Study
. 2024 Jun;35(6):e14175.
doi: 10.1111/pai.14175.

Nirsevimab immunization's real-world effectiveness in preventing severe bronchiolitis: A test-negative case-control study

Marta Agüera  1 , Aleix Soler-Garcia  1   2   3 , Carme Alejandre  4 , Sara Moussalam-Merino  1 , Pere Sala-Castellví  4   5 , Gemma Pons  1 , Daniel Penela-Sánchez  2   6 , Carla González-Grado  1   7 , Judit Alsina-Rossell  1 , Carme Climent  4   5 , Cristina Esteva  2   8 , Clàudia Fortuny  2   3 , Mariona-F de-Sevilla  1   2   3   8 , Juan-José García-García  1   2   3   8 , Pedro Brotons  2   4   8 , Albert Balaguer  4 , Josep Estrada  7 , Iolanda Jordan  2   3   6   8 , Carmen Muñoz-Almagro  2   4   8   9 , Cristian Launes  1   2   3   8
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Free article
Multicenter Study

Nirsevimab immunization's real-world effectiveness in preventing severe bronchiolitis: A test-negative case-control study

Marta Agüera et al. Pediatr Allergy Immunol. 2024 Jun.
Free article

Abstract

Background: Several clinical trials have shown that nirsevimab, an antibody targeting the respiratory syncytial virus (RSV), reduces RSV bronchiolitis requiring admission. In 2023-2024, Catalonia and Andorra adopted immunization strategies for children <6 months and those born during the epidemic season. This study evaluates the effectiveness of nirsevimab in preventing hospitalizations from RSV bronchiolitis.

Methods: In the epidemic season of 2023-2024, a test-negative case-control study was conducted in three hospitals from Catalonia and Andorra. Patients <12 months old admitted with bronchiolitis and tested for RSV using molecular microbiology tests were included. The effectiveness in preventing RSV bronchiolitis hospitalization and severe disease was estimated using multivariate models. Comparisons between immunized, non-immunized, and non-eligible patients were made in prospectively collected epidemiological, clinical, and microbiological variables.

Results: Two hundred thirty-four patients were included. RSV was detected in 141/234 (60.2%), being less common in the immunized group (37% vs 75%, p < .001). The rate of immunized patients among those eligible was 59.7%. The estimated effectiveness for RSV-associated lower respiratory tract infection was 81.0% (95% confidence interval: 60.9-90.7), and for preventing severe disease (the need for NIV/CMV), 85.6% (41.7-96.4%). No significant differences by immunization status were observed in patients with RSV concerning viral coinfections, the need for NIV/CMV or length of hospital stay.

Conclusions: This study provides real-world evidence of the effectiveness of nirsevimab in preventing RSV-lower respiratory tract infection hospitalization and severe disease in infants during their first RSV season following a systematic immunization program. Immunized patients did not exhibit a higher rate of viral coinfections nor differences in clinical severity once admitted.

Keywords: bronchiolitis; effectiveness; immunization; nirsevimab; pediatrics; severity.

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References

REFERENCES

    1. Li Y, Wang X, Blau DM, et al. Global, regional, and national disease burden estimates of acute lower respiratory infections due to respiratory syncytial virus in children younger than 5 years in 2019: a systematic analysis. Lancet. 2022;399:2047‐2064. doi:10.1016/S0140-6736(22)00478-0
    1. Stein RT, Bont LJ, Zar H, et al. Respiratory syncytial virus hospitalization and mortality: systematic review and meta‐analysis. Pediatr Pulmonol. 2017;52:556‐569. doi:10.1002/ppul.23570
    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
    1. Vila J, Lera E, Andrés C, et al. The burden of non‐SARS‐CoV2 viral lower respiratory tract infections in hospitalized children in Barcelona (Spain): a long term, clinical, epidemiologic and economic study. Influenza Other Respi Viruses. 2023;17:e13085. doi:10.1111/irv.13085
    1. Martinón‐Torres F, Carmo M, Platero L, et al. Clinical and economic hospital burden of acute respiratory infection (BARI) due to respiratory syncytial virus in Spanish children, 2015‐2018. BMC Infect Dis. 2023;23:385. doi:10.1186/s12879-023-08358-x

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