Preventive medicine includes various measures taken to prevent disease. Diseases and disabilities are influenced by environmental, genetic and other factors, leading to pathogens and lifestyles, and are dynamic processes that may occur before an individual perceives that he or she is affected. Preventive medicine is the pre-prepared action and measure before the onset of the disease, which can be divided into primary, primary, secondary and tertiary prevention.
Do we have any evidence that wearing a mask is effective in preventing COVID-19?
There is several pieces of evidence to prove the efficacy of masks, one of which comes from laboratory studies of respiratory droplets and the ability of various masks to block droplets. Therefore, simply wearing a mask is a simple action and measure of preventive medicine.