COVID-19 infection has been linked to an increased risk of respiratory type-2 inflammatory diseases, while vaccination appears to offer a protective effect, according to a large-scale USA database study.
Although viral infections are known to drive immune dysregulation, the specific impact of COVID-19 infection and vaccination on type-2 inflammatory diseases across multiple organ systems has been unclear. To address this, researchers conducted a retrospective matched cohort study using electronic health records from over 118 million patients. Three cohorts were defined: individuals with confirmed COVID-19 infection (n=973,794), those who received COVID-19 vaccination (n=691,270), and unexposed controls (n=4,388,409). Propensity-score matching was employed to balance demographic and clinical factors, and hazard ratios were calculated for new-onset asthma, allergic rhinitis, chronic rhinosinusitis, atopic dermatitis, and eosinophilic oesophagitis over a three-month follow-up period.
The analysis revealed that COVID-19 infection significantly increased the risk of several respiratory type-2 inflammatory diseases. The hazard ratio (HR) for new-onset asthma was 1.656 (95% CI: 1.590–1.725), while allergic rhinitis carried an HR of 1.272 (1.214–1.333), and chronic rhinosinusitis had the highest risk at 1.744 (1.671–1.821). No significant association was found between infection and either atopic dermatitis or eosinophilic oesophagitis.
In contrast, vaccination was associated with reduced risk: asthma incidence decreased with an HR of 0.678 (0.636–0.722), and chronic rhinosinusitis showed an HR of 0.799 (0.752–0.850). Direct comparisons indicated that infection carried a two- to threefold greater risk of respiratory type-2 inflammatory disease than vaccination.
These findings suggest that COVID-19 infection acts as a risk factor for new-onset asthma, allergic rhinitis, and chronic rhinosinusitis, whereas vaccination provides measurable protection against respiratory type-2 inflammatory complications. The study highlights the importance of vaccination not only in preventing acute COVID-19 outcomes but also in reducing long-term immunological and respiratory consequences.
Reference
Olbrich H et al. COVID-19 infection raises respiratory type-2 inflammatory disease risk, whereas vaccination is protective. J Allergy Clin Immunol. 2025; DOI:10.1016/j.jaci.2025.07.030.
