Pandemics such as influenza, smallpox, and plague have caused the loss of hundreds of millions of lives and have occurred for many centuries. Fortunately, they have been largely eliminated by the use of vaccinations and drugs. More recently, Severe Acute Respiratory Syndrome (SARS), Middle East Respiratory Syndrome (MERS), and now Coronavirus Disease 2019 (COVID-19) have arisen, and given the current absence of highly effective approved vaccines or drugs, brute-force approaches involving physical barriers are being used to counter virus spread. A major basis for physical protection from respiratory infections is eye, nose, and mouth protection. However, eye protection with goggles is problematic due to "fogging", while nose/mouth protection is complicated by the breathing difficulties associated with non-valved respirators. Here, we give a brief review of the origins and development of face masks and eye protection to counter respiratory infections on the basis of experiments conducted 100 years ago, work that was presaged by the first use of personal protective equipment, "PPE", by the plague doctors of the 17th Century. The results of the review lead to two conclusions: first, that eye protection using filtered eye masks be used to prevent ocular transmission; second, that new, pre-filtered, valved respirators be used to even more effectively block viral transmission.
COVID-19 and Other Pandemics: How Might They Be Prevented?