The Interplay Between Respiratory Syncytial Virus and Asthma Inception: Insights Gained From the COVID‐19 Pandemic

ABSTRACT Background Respiratory syncytial virus (RSV) infection in the first year of life has been linked with an increased risk for asthma. Some propose that RSV‐induced inflammation leads to lasting airway changes, while others contend that RSV bronchiolitis is a marker for underlying predisposition. Social distancing adopted during the COVID‐19 pandemic has led to a dramatic reduction in RSV activity, providing an unexpected opportunity to investigate this debate. Objective To compare the incidence of asthma‐related healthcare‐utilization (HCU) in 1–3 years of age between children born in March–June 2020 (l‐RSV) and children born during the same months in the years 2014–2017 (H‐RSV). Study Design and Methods This retrospective study utilized nationwide healthcare database records from Clalit‐Healthcare‐Services, the largest healthcare organization in Israel. The study analyzed asthma‐related HCU, using multivariate logistic regression and Bayesian analyses. Results 172,463 children were included in the study: 32,927 in the l‐RSV group versus 139,536 in the H‐RSV group. The l‐RSV cohort showed insignificant changes and increased rates of asthma‐related HCU between 1 and 3 years of age in some asthma surrogates, compared to the H‐RSV group. Conclusion Reduction in RSV exposure during the first year of life did not correlate with a decrease in asthma‐related HCU. This may imply that RSV infection in infancy functions as an indicator of underlying predisposition rather than a direct cause of asthma.