Can a mask protect me from coronavirus?

Although face masks reduce the likelihood of transmission by blocking the most common entryways of the virus, there are several reasons why they do not completely prevent infection.

People wearing protective face masks use a smartphone on a street amid coronavirus (COVID-19) concerns (photo credit: REUTERS/VALENTYN OGIRENKO)
People wearing protective face masks use a smartphone on a street amid coronavirus (COVID-19) concerns
(photo credit: REUTERS/VALENTYN OGIRENKO)
Now is a time of global uncertainty and misinformation. In our fight against COVID-19, the hyper-responsive 24-hour news cycle can act as a double-edged sword. Our social media feed is equally capable of doling out misinformation as well as facts, so it is up to scientists, medical professionals, and public health officials like us to debunk the myths and misconceptions about coronavirus as they arise.

Unmasking the Controversy
Although face masks reduce the likelihood of transmission by blocking the most common entryways of the virus – the nose and mouth – there are several reasons why they do not completely prevent infection. First, the vast majority of people don’t know how to put on, remove, or dispose of them correctly, or are not wearing the right size to create a proper seal. Without a seal, plenty of air and viral particles can enter through the sides. Additionally, the virus can still enter through the eyes and ears, or it can deposit on the outer layer of the mask and cause infection when you touch your mask during removal, disposal, or adjustment, and then touch your face.
Ideally, everyone would wear face masks, because they do reduce transmission; coronaviruses are mainly spread by breathing, coughing, and sneezing. However, we have a limited supply of masks and protective equipment. Priority should go to front-line healthcare workers, essential service providers, and immunocompromised folks who are most at risk of infection. The exception to this rule is if you come down with a fever or shortness of breath: then you need to wear a mask and contact your local EMS/COVID-19 hotline for testing. To properly put on a face mask, first apply the ear straps, then shape the metal bar tightly around your nose, then move the bottom part of the mask down so that it covers your chin, and finally, press around the sides of the mask to create a seal.
No personal protective equipment short of a hazmat suit is 100% effective, and most masks are limited by airflow around the sides of your face. That said, N95 masks are used to prevent exposure to aerosols, which are particles less than five microns in diameter. Coronavirus is transmitted primarily through droplets, which are larger, so regular surgical masks may suffice – with a proper fit and seal. At the pharmacy, there were packages of four surgical masks for NIS 19.90, whereas a single N95 mask, which costs NIS 59.90, provides similar protection at 12 times the cost! Save your money by choosing regular surgical face masks, and buy sparingly to save enough for those who need them most.

What if I’m young and healthy?
We aren’t overly worried about young and healthy people, and you quite possibly will not even know you have coronavirus, as many young people do not show symptoms (although a small percentage have ended up in emergency care). That’s the problem: there may already be tens of thousands of young people who are infectious but asymptomatic, so the most recent health guidelines instruct young people to avoid elderly and high-risk individuals.
People over the age of 70 have an up to 15% chance of death from COVID-19, which are terrifying odds. These numbers could double once ventilators, lung bypass machines and standard emergency care are over capacity. If a healthcare system becomes overwhelmed, the one-in-six fatality rate could balloon to one-in-three.
Let’s compare two affected countries. South Korea was one of the first to be hit hard with coronavirus. It also leads the pack in hospital beds per capita in the world and COVID-19 testing rate. Their death rate is just over 1%. Meanwhile, Italy has among the lowest number of COVID-19 test kits and hospital beds per capita and its healthcare system was easily overwhelmed. While South Korea was squarely near the top in number of cases for quite some time, Italy floundered. It shot past South Korea in the number of cases and its mortality rate is above 9%.
The other at-risk population we are concerned about is immunocompromised folks and people with pre-existing conditions, such as chemotherapy patients, HIV/AIDS patients, folks with chronic health conditions like cystic fibrosis, cardiovascular disease, diabetes, lung damage, and people on immunosuppressants after organ transplants or for treatment of autoimmune diseases. These groups are estimated to represent at least 3.6% of the US population, or 10 million people.
There are no projections regarding how many might die in a widespread, unchecked COVID-19 pandemic, but the numbers would likely be in the millions. It’s almost certain that you know at least one person in this category, and you may even have the potential to become one: you might be high-risk due to a pre-existing condition that you don’t even know about yet. Now is not the time to find this out, which is why social distancing is one of the most effective tools we have for combating the spread of COVID-19.

COVID-19 vs. the flu
According to preliminary studies, in almost all cases requiring treatment, coronavirus patients present with a fever over 38° centigrade. In almost all cases of the common cold, and in a substantial amount of flu cases, patients do not have a fever. From anecdotal reports, the fever from coronavirus appears to come on very quickly, and persists for longer than the seasonal flu. Although a runny nose is relatively common for the flu or a cold, less than 20% of folks with coronavirus presented with a runny nose. Additionally, while a dry cough is common for the coronavirus (up to 75% of patients), a wet (or mucus-producing) cough is not, at least in the early stages of COVID-19. Wet coughs come only later, once the virus moves to the lower airways and causes shortness of breath and pneumonia. If your illness starts with a wet cough, you almost certainly don’t have coronavirus.
The usual symptom profile of coronavirus (in order of appearance) includes: onset with high fever and possible throat irritation, followed by a dry cough and eventually shortness of breath (often manifested by wheezing or dyspnea – trouble breathing), although some studies suggest only 20% to 25% of coronavirus patients experience shortness of breath and are hospitalized. Meanwhile, only about 1% of people with the flu are hospitalized, and only 0.1% do not survive, compared to 20% of COVID-19 patients hospitalized and around a 3% mortality.
 
Asymptomatic transmission?
Right now we suspect (although this is tricky to prove) that asymptomatic carriers are the major transmitters, which differentiates COVID-19 from other epidemics. This is why people who may have been exposed to the coronavirus need to self-isolate for 14 days, because the virus can incubate for 14 days or more without producing symptoms, but carriers can still shed viral particles just from breathing. Recently, the head of Epidemiology at the Health Ministry discussed the danger of asymptomatic carriers at length, which reinforces the need for social distancing and self-isolation. The bottom line: while symptomatic carriers are certainly more infectious, especially if they don’t maintain proper hygiene, such as coughing into the elbow, frequent hand washing, avoiding physical contact, social distancing, and mask-wearing, asymptomatic carriers are a huge part of what makes this virus so insidious, and they are one of the reasons countries have been taking such extreme measures to prevent transmission.

Re-Infection?
The evidence for this is mixed because it’s still early in the outbreak, but it seems possible to be re-infected with coronavirus, because we know of at least two, but as many as five strains of coronavirus are already circulating. This is similar to the seasonal flu, which is highly mutable and comes back every year with a slightly different set of strains to re-infect the population.

Cure?
There is currently no cure or vaccine for COVID-19. Although scientists around the world are working to confirm the efficacy of several trial vaccines, there is no drug or injection on the market as of yet. It isn’t all bad news, though: clinicians have found that Tamiflu, an influenza medication, is capable of reducing symptoms and longevity of disease; moreover, acetaminophen (Tylenol) also helps with symptoms.

Alexandra Markus Hutz, an adjunct professor of biomedical sciences at Shelem College, is in her last semester of her master of public health at Hebrew University. She has worked as a biomedical scientist researching the impact of vitamin D on tuberculosis infection and progression, and as an assistant epidemiologist at the Health Ministry. She is passionate about promoting scientific and health literacy in the wider community.
Jamie Magrill is currently completing his master of science in Biomedical Sciences at Hebrew University. He has conducted research in the fields of cancer, diabetes and pathology for the past five years and co-authored scientific journal articles in publications like Cell Metabolism, Annals of Oncology and The Journal of Pathology. He has worked in science outreach as an educator, workshop facilitator and lecturer since 2017.