Introduction:
“The novel coronavirus SARS-CoV-2 (COVID-19) was recognized in December 2019 as a cause of severe pneumonia and has now led to a global pandemic.1 Respiratory illnesses caused by COVID-19 cover a range of severity. The identification of risk and protective factors for disease severity from COVID-19 is critical to direct development of new treatments and infection prevention strategies. Early large case series have identified a number of risk factors for severe disease, including older age, hypertension, diabetes, cardiovascular disease, tobacco exposure, and chronic obstructive pulmonary disease.2 The US Centers for Disease Control and Prevention lists asthma as a risk factor for severe COVID-19 illness, which is logical given that many respiratory viruses have been well established to cause more serious illnesses in those with chronic airway diseases such as asthma. However, asthma and respiratory allergy have not been identified as significant risk factors for severe COVID-19 illness in case series from China.2 These preliminary reports led us to question whether we could identify features of allergy and/or asthma that could be associated with potential for reduced severity of COVID-19 illness………”
Jackson DJ et al: Association of respiratory allergy, asthma, and expression of the SARS-CoV-2 receptor ACE2. J. Allergy Clin. Immunol. 146(1): 203–206.e3 (2020).
https://pubmed.ncbi.nlm.nih.gov/32333915/