US COVID-19 survivors are at higher risk for type 2 inflammatory diseases (T2IDs) of the airways, such as asthma, hay fever, and chronic sinusitis (sinus infection), a risk that can be mediated by vaccination, a group of international researchers suggest in The Journal of Allergy and Clinical Immunology.
In fall 2024, the team analyzed electronic health records to assess the risk of new-onset T2IDs after COVID-19 infection and vaccination. They compared adult COVID-19 survivors with uninfected, unvaccinated controls (940,436 participants each), vaccinated participants with controls (691,270 each), and infected and vaccinated participants (688,279 each).
The studied diseases were incident asthma, allergic rhinitis (hay fever), chronic rhinosinusitis, atopic dermatitis, and eosinophilic esophagitis. Follow-up was 3 months.
Infection raised risk of asthma 66%
Compared with controls, COVID-19 survivors were at a 65.6% higher risk of asthma, as well as at an elevated risk for allergic rhinitis (27.2%) and chronic rhinosinusitis (74.4%). The risks of atopic dermatitis or eosinophilic esophagitis stayed steady.
The findings were consistent through all five sensitivity analyses, with an even more pronounced risk difference in both the third (extended propensity score matching) and fourth (ensured follow-up), with the third showing a roughly doubled risk of both asthma and chronic rhinosinusitis.
In contrast, COVID-19 vaccination reduced the risk of asthma by 32.2%, with significant but smaller reductions for allergic rhinitis and chronic rhinosinusitis. No change was observed for atopic dermatitis or eosinophilic esophagitis.
Direct comparison of infection and vaccination showed a two- to threefold higher risk of respiratory T2IDs with infection than with vaccination, which held in all sensitivity analyses. The results for respiratory T2IDs were consistent in all sensitivity analyses except the third, in which the significance was lost for all conditions except asthma.
'Risks were notably mitigated by vaccination'
"Our large-scale matched cohort study demonstrates a heightened risk of respiratory T2IDs, namely allergic asthma, allergic rhinitis and chronic rhinosinusitis, in adults following COVID-19 infection," the study authors wrote.
"These risks were notably mitigated by vaccination, with the largest risk differences observed between infection-naïve vaccinated individuals and unvaccinated infected individuals."
