(RICO’S COVID-19) If masks prevent the spread of the coronavirus, why do doctors and nurses often get infected while wearing all the PPE, including masks?
A question that is commonly used by those against using a mask, even in the midst of a rise in coronavirus cases.
Wearing a mask should no longer the question, rather “what kind of face mask should I wear?”.
The World Health Organization (WHO), the Centers for Disease Control and Prevention (CDC), and the National Institute for Health (NIH) are all in agreement: wear face masks.
No face mask of any kind is 100% effective. Even an N95 won’t save you if you touch your face with contaminated hands right after you take it off. Face masks must be used in combination with distancing and washing your hands, among other protective measures.
So, back to the question. The answer is because it’s the amount of virus you are exposed to that matters, both in how likely you are to get infected, and how sick you are likely to become.
Even when wearing a mask, even an N95 won’t save you. Some virus particles can always get through the filter material, sneak around the mask on a drop of sweat or misplaced finger, settle in the eyes, and enter the body.
In most cases, very small quantities of a virus – even an infectious virus like the COVID-19 – will be destroyed by the body’s innate immunity, the body attacking any foreign material not recognized as part of itself.
If exposure is low enough, the innate immunity is generally sufficient.
This is as opposed to acquired immunity, such as a vaccine, which involves antibodies and antigens to help create a rapid powerful response to a known pathogen, without experiencing the illness.
But doctors, nurses, even the cleaning staff, are different. They are constantly exposed to the virus. When they get off shift or take a break, they can count on having the virus all over them.
If they wear a face mask, shield, and gloves, they will greatly reduce their exposure. Virus particles are very, very small, and can linger in the air for an unknown period of time and can fly off of gowns and clothing as they are removed.

Estéfani Vargas, the Coordinator of General Services of the Specialized Center for the Care of Patients with COVID-19 (CEACO), told Telenoticias that, to perform her job properly, she has to bathe up to six times a day.
Vargas, a 31-year-old industrial engineering student working for the Costa Rican Social Security Fund (CCSS) for six months, said that she and her colleagues put on double gloves and double masks and make sure that none of their body is exposed when they enter to clean the patient areas.
The take on all this is that if you are constantly exposed at a high enough level because say you work in a hospital with COVID-19 patients or have prolonged exposure to someone is infected, knowingly or not, such as being in contact with an asymptomatic person, you may get very sick, even if you are young and fit and otherwise not at great risk.
If you are constantly exposed at a low level, your innate immunity may be overwhelmed or exhausted, and you can get sick.
Bottom line: No face mask of any kind of magical answer. Wearing a mask alone will not prevent you or someone you love from becoming infected with COVID-19. But wearing one yourself, even if nobody else around you, reduces your own chances of catching the virus.
The other bottom line: Don’t forget, face masks used in combination with physical distancing and hand hygiene, and other protective measures reduce the risk even more.
The last bottom line: Personally I am doing my best to avoid catching the COVID-19. If were to catch it, I will deal with it. But I prefer not to.