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

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.