Effect of background asthma and atopic conditions on prophylaxis and treatment of COVID-19 infection

BACKGROUND: Electronic medical record database studies suggest that underlying allergic diathesis is a risk factor for COVID-19 but may attenuate outcomes.

OBJECTIVE: To evaluate the effect of background atopic conditions on outcomes across clinical trials in patients with and without COVID-19 treated with casirivimab plus imdevimab (CAS + IMD).

METHODS: This analysis included 4057 outpatients with acute COVID-19. Supplementary analyses involved 2652 patients without COVID-19, investigating prevention in the home or community settings. Participants were randomized to CAS + IMD or placebo. Participants with atopic conditions were identified by medical history and categorized as follows: (1) any atopic condition; (2) atopic conditions excluding asthma; (3) asthma excluding other atopic conditions; and (4) no atopic conditions. Assessments included time to hospitalization/death and change in viral load from baseline to day 7 analyzed using adjusted regression methodologies.

RESULTS: Among placebo subjects, the adjusted risk of hospitalization/death was 52% lower in those with an atopic background without asthma vs those without atopy (hazard ratio [HR]: 0.48; 95% CI, 0.31-0.74; P < .001). The adjusted risk of hospitalization/death in patients receiving placebo was 2.90 times higher for those with asthma only vs those without atopic conditions (HR, 2.90; CI, 1.55-5.48; P < .001). The HR for hospitalization/death for CAS + IMD vs placebo was 0.26 for patients without atopy (CI, 0.12-0.58; P < .001), 0.17 (CI, 0.06-0.49; P < .001) for patients with atopic conditions excluding asthma, and 0.32 (CI, 0.16-0.63; P < .001) for those with asthma only. In the prevention studies, unvaccinated subjects with atopic conditions excluding asthma exhibited more than 2-fold increase in the rate of contracting COVID-19 vs those without atopy (HR, 2.10; CI, 1.05-4.21; P = .037). Adjustment for imbalance in antihistamine use had little effect on estimates.

CONCLUSION: In COVID-19 prevention and treatment, atopic disease was associated with heightened susceptibility to infection but better clinical outcomes. CAS + IMD improved clinical outcomes in both cases.