Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
Observational Study
. 2025 Mar 13;184(4):246.
doi: 10.1007/s00431-025-06057-0.

Distinct seasonality and increased respiratory failure in RSV patients < 2 years of age after emergence of SARS-CoV-2: data from the multicentric, prospective PAPI study

Jessica Bähre  1 , Matthias Lange  2 , Patrick Salaschek  3 , David Twardella  4 , Stefan Arens  1 , Frank Eberhard  5 , Grit Barten-Neiner  5 , Marcus Panning  6 , Holger Köster  2 , Cordula Körner-Rettberg  3 , Martin Wetzke  7   8   9 , Christine Happle  10   11   12
Affiliations
Observational Study

Distinct seasonality and increased respiratory failure in RSV patients < 2 years of age after emergence of SARS-CoV-2: data from the multicentric, prospective PAPI study

Jessica Bähre et al. Eur J Pediatr. .

Abstract

Respiratory syncytial virus (RSV) is a leading cause for global infant morbidity and mortality. The COVID-19 pandemic caused significant shifts in seasonality of RSV, and changes in disease severity have been matter of intense discussion. Between September 2020 and February 2023, the multicentric, prospective PAPI study analyzed rates and phenotypes of hospitalized RSV patients aged ≤ 24 months across three German hospitals. Pseudonymized patient data were analyzed employing Mann-Whitney U and chi-square testing, or one-way ANOVA or Kruskal-Wallis testing when more than two groups were compared. Additionally, RSV cases from seasons 2017/2018-2020/2021 were retrospectively analyzed. After its absence in 2020/2021, RSV returned approximately 2 months earlier than usual in late 2021. Overall duration of the season and patient numbers were comparable to previous seasons, and no significant shifts in age and gender distributions occurred in our cohort. While duration of hospitalization did not differ between the periods before vs. after the emergence of SARS-CoV-2, a significantly higher rate of patients with hypoxemia and respiratory failure occurred after the onset of the pandemic (oxygen supplementation post vs. pre: 59.4% vs. 54.8%, p < 0.001, non-invasive ventilation post vs. pre: 12.4% vs. 7.2%; p < 0.001). No deaths occurred during the entire observational period.

Conclusion: We present comprehensive data on distinct seasonality and increased disease severity in children hospitalized with RSV bronchiolitis before and after the onset of the SARS-CoV-2 pandemic. Our data aids in understanding the impact of the pandemic on RSV disease in infants and provides valuable information on the impact of RSV on pediatric healthcare prior to broad introduction of novel prevention measures such as nirsevimab.

What is known: • Respiratory syncytial virus (RSV) is a leading cause of infant morbidity and mortality globally. • COVID-19 has led to significant shifts in RSV seasonality, and concerns about shifts in RSV severity.

What is new: • This study shows distinct seasonality and significant shifts in diseases severity amongst children with RSV associated hospitalization under the age of 2 yrs in the last years in Germany. • It reports significantly higher rates of RSV associated respiratory failures in children < 2 yrs. of age after emergence of the pandemic.

Keywords: COVID-19; Pandemic; RSV; Resurgence; Seasonality.

PubMed Disclaimer

Conflict of interest statement

Declarations. Ethics approval and consent to participate: All study procedures were conducted in accordance with the Declaration of Helsinki, and all local Medical Ethics Committees of the participating centers approved the study protocol (e.g., ethics approval Hannover Medical School #9442_BO_K_2020 MHH). For the prospective data analysis, the legal guardians of all participants gave written informed consent. Consent for publication: This manuscript contains no individual patient data in any form. Competing interests: The PAPI study was funded by Sanofi/AstraZeneca to MW. The funder did not influence the design of the study or the collection, analysis, and interpretation of the data or writing of the manuscript. Martin Wetzke received funding from the German Center for Infection Research (DZIF). Christine Happle received funding from the Excellence Cluster RESIST in infection research. MW received consulting and speaking fees from Novartis, GSK und Abbott.

Figures

Fig. 1
Fig. 1
Number of patients per calendar week across seasons
Fig. 2
Fig. 2
Sex (A) and age group (B) distribution across seasons. Median ages of patients in the analyzed seasons (C). (Donut pies in A and B show the distribution of items per season in concentrical circles; bars in C display median with box and whiskers)
Fig. 3
Fig. 3
RSV risk factors and palivizumab treatment rates across seasons. A Prematurity (< 37.0 weeks of gestation). B Rates of heart defect and C palivizumab treatment rates across seasons (donut pies display distribution of items per season in concentrical circles)
Fig. 4
Fig. 4
Disease severity and treatment demand across seasons. A Duration of hospitalization. B Rates of and C duration of oxygen supplementation. D Rates of ventilation and E, F rates of non-invasive (NIV) and invasive (IV) ventilation (bars in A and C display box and whiskers; donut pies in B and D–F display distribution of items per season in concentrical circles)
See this image and copyright information in PMC

References

    1. Pneumonia Etiology Research for Child Health Study G (2019) Causes of severe pneumonia requiring hospital admission in children without HIV infection from Africa and Asia: the PERCH multi-country case-control study. Lancet 394(10200):757–779 - PMC - PubMed
    1. Hak SF, Sankatsing VDV, Wildenbeest JG, Venekamp RP, Casini B, Rizzo C, Bangert M, Van Brusselen D, Button E, Garcés-Sánchez M at al.. Burden of RSV infections among young children in primary care: a prospective cohort study in five European countries (2021-23). Lancet Respir Med. 2025 Feb;13(2):153-165. doi: 10.1016/S2213-2600(24)00367-9. Epub 2025 Jan 9. - PubMed
    1. Li Y, Wang X, Blau DM, Caballero MT, Feikin DR, Gill CJ, Madhi SA, Omer SB, Simoes EAF, Campbell H et al (2022) 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 399(10340):2047–2064 - PMC - PubMed
    1. Rafferty E, Paulden M, Buchan SA, Robinson JL, Bettinger JA, Kumar M, Svenson LW, MacDonald SE (2022) Canadian Immunization Research Network i: Evaluating the individual healthcare costs and burden of disease associated with RSV across age groups. Pharmacoeconomics 40(6):633–645 - PMC - PubMed
    1. Noble M, Khan RA, Walker B, Bennett E, Gent N (2022) Respiratory syncytial virus-associated hospitalisation in children aged </=5 years: a scoping review of literature from 2009 to 2021. ERJ Open Res 8(2) - PMC - PubMed

Publication types

MeSH terms

LinkOut - more resources