Our highest quality evidence shows that masks do not reduce the spread of viral respiratory illnesses such as COVID-19. Why?
Many have said that “if a mask is good enough for my doctor to wear during surgery, then it’s good enough for me to wear to stop the spread of COVID-19.” This reflects a fundamental misunderstanding. Masks are used in surgery solely to stop surgical (wound) infections, not respiratory infections. There is no reason to believe that wound infections are transmitted the same way as respiratory infections. Accordingly, there is no reason to believe that using a tool (masks) designed to stop wound infections will stop respiratory infections.
Wound infections can be caused by large-droplet spittle from the surgeon into the surgical wound. Masks stop these droplets. Viral respiratory infections are spread primarily by very fine aerosol particles that escape freely all around the edges of a mask, and also by surface transmission on doorknobs, etc. Surface transmission occurs when virus-laden respiratory secretions are spit, coughed, or sneezed onto a surface, or more likely, spread from one’s hand to a surface after touching the face where respiratory secretions can accumulate.
Dr. Anthony Fauci referenced this in March when he stated that masks should not be worn during viral outbreaks. Masks increase the chance that a person will touch his or her face where respiratory secretions accumulate, causing that person to leave the virus on more surfaces than if a mask were not worn.
Follow the science. Take off your mask!