On World Asthma Day (May 5) the European Respiratory Society (ERS) stated: “Use of inhaled corticosteroids effectively prevents asthma symptoms, and there is some evidence to suggest that ICS use is associated with reduced expression of ACE-2.”16

Angiotensin converting enzyme (ACE-2) is present in many different tissues including lung tissue. The Covid-19 virus appears to have an affinity for ACE-2, and lung cells expressing higher levels of ACE-2 seem to be more readily infected by the virus. It is also possible that Covid-19 infects other tissues besides the lungs.17

Based on the early evidence, the ERS has suggested that “use of ICS is linked to reduced expression of this molecule (ACE-2); in theory this could contribute to protecting against Covid-19, but more research is needed to confirm this”.16

The data also suggest there is not a significant difference in infectivity levels between sexes or ages. However, immune responses may be smaller in females and young people compared to males and older people. The effects of an excessive immune response – cytokine storm or immunopathological damage – could therefore be more likely in males and old people with Covid-19 infection.17