to date, there have been several cohort studies that have linked covid-19 infection in both adults and children. kim utilized the korean national health insurance claim-based database to design three cohorts for adults and found that 1.6% of the covid-19 group and 0.7% of the non-infected group developed asthma during the 6-month observation period. the covid-19 cohort faced a higher risk of new-onset asthma (ahr 2.14; 95% ci 1.882.45) than matched controls, aligning with our findings. kim noted that vaccinated infected individuals had a lower asthma risk compared to their unvaccinated counterparts (ahr 0.82; 95% ci 0.760.89). however, vaccination did not reduce asthma risk in those uninfected by covid-19 (ahr 0.95; 95% ci 0.871.04) [6]. a study with cohorts from south korea, japan, and the uk shows a significant rise in allergic diseases like asthma and allergic rhinitis after covid-19, persisting over six months and worsening with disease severity. vaccination with at least two covid-19 doses provided protection [7]. as for children, there is limited and inconclusive literature on the risk of asthma following covid-19 infection in children. a small sample size retrospective chart review revealed that most children diagnosed with covid-19 had normal spirometry and plethysmography results [39]. furthermore, a retrospective cohort study using ehr data from a single institution within the childrens hospital of philadelphia care network found no association between sars-cov-2 pcr positivity and new asthma diagnoses in children aged 116 over an 18-month follow-up period (hr: 0.96; p=0.79).8 interestingly, another study indicated that an asthma diagnosis was negatively associated with covid-19-related hospitalization in children [9]. to date, no strong evidence has been published in the literature to suggest a positive or negative association between covid-19 and new-onset asthma in children.
United States