The diplomacy of tobacco smoke with COVID-19: A commentary

The impact of tobacco smoke and its association with COVID-19 severity has been a topic of ongoing debate since the onset of the pandemic. However, the balance between the two and their relationship in synergism or antagonism needs a thorough probing. It is to be believed with the current scientific evidence that the structural changes in the angiotensin-converting enzyme-2 (ACE2) allelic variants can interfere with the intermolecular interactions of such variants with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) spike protein. Upon nicotinic stimulation, some ACE2 allelic variants that inhibit the SARS-CoV-2 binding may undergo positive selection. Nicotine interacts with renin–angiotensin system in multiple organ systems. These findings have putatively important implications for patients with COVID-19 because ACE2 has been shown to be the receptor used by SARS-CoV-2 to enter the host cells and yet seems in disparity with the epidemiological data available globally indicating a low prevalence of active smokers among patients with COVID-19. To further emphasize the finding, it may be speculated that the effect of current smoking on SARS-CoV-2 infection is a delicate and complex topic that should be addressed meticulously before delivering messages that could be misinterpreted.