Smokers may be prone to severe COVID-19 infections, in part, because their lungs contain an abundance of entry points that the virus can exploit.
COVID-19 infections begin at the ACE2 receptor, a protein nestled on the surface of cells throughout the body, including in the upper and lower respiratory tracts. The coronavirus that causes COVID-19, known as SARS-CoV-2, must plug into the ACE2 receptor in order to inject its genetic material into cells, replicate and spread. Now, preliminary research suggests that lungs exposed to cigarette smoke accumulate abnormally large numbers of ACE2 receptors, which may leave the organ vulnerable to damage inflicted by the coronavirus.
Link to the paper: https://doi.org/10.1101/2020.03.28.013672
Editorial Disclaimer: information published during the 2020 COVID-19 pandemic may be updated frequently to reflect the dynamic nature of current understanding.