The effectiveness of the palivizumab programme in reducing the risk of paediatric asthma: a population‐Based study in Ontario, Canada
Author(s)
Type
Journal Article
Abstract
Background
Palivizumab was introduced in Canada in 1998 as a publicly funded programme to reduce respiratory syncytial virus (RSV) disease in high-risk children. Severe early-life RSV infections are associated with increased asthma risk. Thus, palivizumab may also indirectly reduce paediatric asthma.
Objective
To evaluate the effectiveness of Ontario, Canada's palivizumab programme in decreasing paediatric asthma.
Methods
We used multiple linked population-based administrative databases to identify all children born in Ontario between 1993 and 2013, with follow-up through March 2020. Our primary outcome was physician-diagnosed asthma by age 7. Controlled interrupted time-series analysis was used to compare changes in annual asthma incidence (by birth year) before and after palivizumab's introduction, according to programme eligibility (clearly, possibly, or ineligible). Socio-demographic differences were explored via stratification.
Results
Nearly 3 million children were included in this study, including 406,596 (14.6%) diagnosed with asthma by age 7. Asthma incidence substantially declined over the study period, with the greatest declines among palivizumab-ineligible children (35.3%, 95% confidence interval [CI] 28.3, 42.6, versus 18.1%, 95% CI 13.9, 22.9 among clearly eligible children). However, relative to ineligible children, post-palivizumab declines were most apparent among possibly eligible children, with an additional annual decline of 2.0% (95% CI 0.3, 3.7) in asthma. Socio demographic differences in asthma incidence and post-palivizumab declines were noted. Particularly, incidence was higher among children born to teenage mothers than among those aged 19+ years; this gap narrowed over time, especially among possibly eligible children.
Conclusions
Asthma incidence declined over this 20-year study; however, smaller declines were observed among children clearly eligible for palivizumab relative to ineligible children. However, exploratory evidence was suggestive of reduced social inequities in asthma post-palivizumab, particularly among possibly eligible children. Larger reductions in asthma might be realized with the introduction of population-based RSV immunization programmes through broader programme eligibility and reductions in severe RSV disease.
Palivizumab was introduced in Canada in 1998 as a publicly funded programme to reduce respiratory syncytial virus (RSV) disease in high-risk children. Severe early-life RSV infections are associated with increased asthma risk. Thus, palivizumab may also indirectly reduce paediatric asthma.
Objective
To evaluate the effectiveness of Ontario, Canada's palivizumab programme in decreasing paediatric asthma.
Methods
We used multiple linked population-based administrative databases to identify all children born in Ontario between 1993 and 2013, with follow-up through March 2020. Our primary outcome was physician-diagnosed asthma by age 7. Controlled interrupted time-series analysis was used to compare changes in annual asthma incidence (by birth year) before and after palivizumab's introduction, according to programme eligibility (clearly, possibly, or ineligible). Socio-demographic differences were explored via stratification.
Results
Nearly 3 million children were included in this study, including 406,596 (14.6%) diagnosed with asthma by age 7. Asthma incidence substantially declined over the study period, with the greatest declines among palivizumab-ineligible children (35.3%, 95% confidence interval [CI] 28.3, 42.6, versus 18.1%, 95% CI 13.9, 22.9 among clearly eligible children). However, relative to ineligible children, post-palivizumab declines were most apparent among possibly eligible children, with an additional annual decline of 2.0% (95% CI 0.3, 3.7) in asthma. Socio demographic differences in asthma incidence and post-palivizumab declines were noted. Particularly, incidence was higher among children born to teenage mothers than among those aged 19+ years; this gap narrowed over time, especially among possibly eligible children.
Conclusions
Asthma incidence declined over this 20-year study; however, smaller declines were observed among children clearly eligible for palivizumab relative to ineligible children. However, exploratory evidence was suggestive of reduced social inequities in asthma post-palivizumab, particularly among possibly eligible children. Larger reductions in asthma might be realized with the introduction of population-based RSV immunization programmes through broader programme eligibility and reductions in severe RSV disease.
Date Issued
2026-05-01
Date Acceptance
2026-03-20
Citation
Paediatric and Perinatal Epidemiology, 2026, 40 (4), pp.484-496
ISSN
0269-5022
Publisher
Wiley
Start Page
484
End Page
496
Journal / Book Title
Paediatric and Perinatal Epidemiology
Volume
40
Issue
4
Copyright Statement
© 2026 The Author(s). Paediatric and Perinatal Epidemiology published by John Wiley & Sons Ltd. This is an open access article under the terms of the Creative Commons Attribution-NonCommercial-NoDerivs License, which permits use and distribution in any medium, provided the original work is properly cited, the use is non-commercial and no modifications or adaptations are made.
Identifier
10.1111/ppe.70141
Subjects
asthma
child health
interrupted time series analysis
palivizumab
respiratory syncytial virus
Publication Status
Published
Date Publish Online
2026-03-31