As more mandatory mask directives are implemented among various cities, states, and businesses, compliance with these directives is often not ideal, with many individuals adopting the practice of half-masking.

Half-masking is the practice of wearing a mask only over the lower half of the face, allowing the nose to be uncovered. But is the practice effective in stopping spread of COVID-19? Or does it cause even more potential disease spread?

According to a study form the University of North Carolina published in the journal Cell, the virus first penetrates and infects the nasal cavity, and at times can travel to the lungs where it can cause pneumonia. The study tracked the virus and mapped where it infiltrated the respiratory tract, noting that it infected the nasal passages most often and decreased infiltration as it progressed down the respiratory path to the throat and lungs. Additionally, the virus targeted ACE2 (angiotensin-converting enzyme-2) cell receptors as its means of entry to the body. These receptors are more abundant in the nasal-lining tissue and less prevalent in the lower portions of the respiratory tract, according to the report. The virus is able to circumvent the normal defense mechanisms of the nasal cells; meanwhile, the nasal cells can allow the virus to reproduce millions of copies once infected.

From there, the virus can penetrate the olfactory tissues in the roof of the nose, leading to the disease symptom of loss of smell, and the salivary glands, leading to the dry mouth symptoms, and ultimately to the lungs, potentially causing shortness of breath, pneumonia, and death.

This study and mechanism of infection progression underscores the importance of wearing a mask properly to cover both the nose and mouth, as half-masking does not prevent the wearer from either spreading or contracting the virus.

Source: Fox News, August 26, 2020