SARS-CoV-2 engages with the angiotensin-converting enzyme 2 (ACE2) host cell receptor, which is found in two forms within the lung. One form of ACE2 is membrane-attached (mACE2), whereas the other is a soluble form of ACE2 (sACE2). [...]
The role of tobacco smoking as a risk factor for severe COVID-19 has been controversial. Some scientists consider it to increase the risk of infection and the severity of the disease. Similarly, vaping, or the use of electronic cigarettes (e-cigarettes) has also been shown to cause toxicity in the lung tissue via the synthesis of noxious proteins as well as through immunologic alterations.