SARS-CoV-2 and Smoker’s Paradox: Mediation by Ciliary Beat Frequency and Mucociliary Clearance?

A COVID-19 smoker’s paradox was identified during the early days of pandemic—many studies reported that smokers appeared to be protected against SARS-CoV-2 infections. Conversely, other added controversy with findings increased risk for in heavy smokers. Ciliary beat frequency (CBF) within ciliated epithelium nasal tract can stimulated a higher and provide protection transient exposure airway irritants. Smokers as well non-smokers exposed secondhand tobacco smoke were found have CBFs. However, extended irritants, persistent upregulated CBF damage remodel epithelial layer fewer protective cilia. Additionally, mucociliary clearance (MCC), innate defense mechanism respiratory system, traps particles pathogens mucous propels them out airways through ciliary activity. this becomes defective disease progresses, increasing susceptibility viral This paper proposes associated infection patients may mediated by beating smoke, downregulated MCC smoke.