Risk Analysis of Respiratory Syncytial Virus Among Infants in the United States by Birth Month

Jason R Gantenberg; Robertus van Aalst; Monika Reddy Bhuma; Brendan Limone; David Diakun; David M Smith; Christopher B Nelson; Angela M Bengtson; Sandra S Chaves; William V La Via; Christopher Rizzo; David A Savitz; Andrew R Zullo

doi:10.1093/jpids/piae042

Risk Analysis of Respiratory Syncytial Virus Among Infants in the United States by Birth Month

J Pediatric Infect Dis Soc. 2024 May 13:piae042. doi: 10.1093/jpids/piae042. Online ahead of print.

Authors

Jason R Gantenberg^{1

2}, Robertus van Aalst^{1

3

4}, Monika Reddy Bhuma¹, Brendan Limone⁵, David Diakun⁵, David M Smith⁵, Christopher B Nelson⁶, Angela M Bengtson⁷, Sandra S Chaves³, William V La Via⁶, Christopher Rizzo⁶, David A Savitz², Andrew R Zullo^{1

2

8}

Affiliations

¹ Department of Health Services, Policy and Practice, Brown University School of Public Health, Providence, Rhode Island, USA.
² Department of Epidemiology, Brown University School of Public Health, Providence, Rhode Island, USA.
³ Department of Modeling, Epidemiology, and Data Science, Vaccines Medical Affairs, Sanofi, Lyon, France.
⁴ Department of Health Sciences, University Medical Center Groningen, University of Groningen, Groningen, the Netherlands.
⁵ Merative, Cambridge, Massachusetts, USA.
⁶ Vaccines Medical Affairs, Sanofi, Swiftwater, Pennsylvania, USA.
⁷ Department of Epidemiology, Emory University, Atlanta, Georgia, USA.
⁸ Providence VA Medical Center, Providence, Rhode Island, USA.

PMID: 38738450
DOI: 10.1093/jpids/piae042

Abstract

Background: Respiratory syncytial virus (RSV) is a major cause of morbidity and mortality among U.S. infants. A child's calendar birth month determines their age at first exposure(s) to RSV. We estimated birth month-specific risk of medically attended (MA) RSV lower respiratory tract infection (LRTI) among infants during their first RSV season and first year of life.

Methods: We analyzed infants born in the USA between July 2016 and February 2020 using three insurance claims databases (two commercial, one Medicaid). We classified infants' first MA RSV LRTI episode by highest level of care incurred (outpatient, emergency department, or inpatient), employing specific and sensitive diagnostic coding algorithms to define index RSV diagnoses. In our main analysis we focused on infants' first RSV season. In our secondary analysis we compared the risk of MA RSV LRTI during infants' first RSV season to that of their first year of life.

Results: Infants born from May through September generally had the highest risk of first-season MA RSV LRTI-approximately 6%-10% under the specific RSV index diagnosis definition and 16%-26% under the sensitive. Infants born between October and December had the highest risk of RSV-related hospitalization during their first season. The proportion of MA RSV LRTI events classified as inpatient ranged from 9%-54% (specific) and 5%-33% (sensitive) across birth month and comorbidity group. Through the first year of life, the overall risk of MA RSV LRTI is comparable across birth months within each claims database (6%-11% under the specific definition, 17%-30% under the sensitive), with additional cases progressing to care at outpatient or ED settings.

Conclusions: Our data support recent national recommendations for the use of nirsevimab in the USA. For infants born at the tail end of an RSV season who do not receive nirsevimab, a dose administered prior to the onset of their second RSV season could reduce the incidence of outpatient and ED-related events.

Grants and funding

R00 MH112413/MH/NIMH NIH HHS/United States