Category: COVID-19

mRNA Vaccines

To understand how mRNA vaccines work, we must first have a basic understanding of cells and genetics. Zzzzzzz. Wait! Before you go to sleep, we’re going to make this really short and really simple. Cells are bags of jelly—jellybeans, so to speak—and in those jellybeans is a kernel called a nucleus. DNA lives in the nucleus, and like the cell’s hard drive, DNA stores and preserves the cell’s genetic code. Genetic code is a series of nitrogen bases strung together to form nucleic acid. There are only four possible bases, so just like computer code is a series of 1’s and 0’s, genetic code is a series of A’s, T’s, G’s, and C’s, each letter standing for a different nitrogen base. DNA is arranged in two complimentary stands—the famous double helix of Watson and Crick—to create code redundancy like mirrored hard drives that protect your data in case of a crash.

When the genetic code needs to be accessed, a specific portion of the DNA untwists, exposing a segment of code which is copied onto a new strand of messenger RNA (mRNA). Unlike DNA, RNA is only a single strand of nucleic acid and much less stable. The mRNA floats into the cell jelly, the cytoplasm, where ribosomes attach and move along the strand, coupling together amino acids as they go. Every sequence of three bases on the mRNA, known as a codon, codes for a specific amino acid. For example, GCA codes for alanine, CAA codes for glutamine, and so on. There are 20 different amino acids, each with its own codon or codons (some have more than one). Put together according to the sequence of bases on the mRNA, the amino acid chains become a protein. Out of the trillions of possible amino acid combinations, the proteins formed by your genetic code define the shape of your nose, the length of your bones, the complexion of your skin and everything else that makes you you. Once the right number of proteins have been made, the mRNA disintegrates into the cytoplasm of the cell. The process starts again in the nucleus, and a new protein is created as called for by the cell.

What if mRNA could be injected directly into cytoplasm without first being created in the nucleus? Then the cell’s machinery could create a protein that wasn’t part of the cell’s genetic code. That’s exactly the hypothesis behind mRNA vaccines. After the vaccine delivers mRNA into the cytoplasm of muscle cells in the arm, those cells begin forming the protein coded by the mRNA in the vaccine—in the case of COVID vaccines, one of the spike proteins known to exist on the SARS-CoV-2 viral capsule—and those proteins make their way to the surface of the cell where the immune system forms antibodies which are memorized by the body for future use. How cool is that!

Various companies have been working on mRNA vaccines for over a decade, but none made it to production until the pandemic demanded rapid vaccine development. Although never been used on a large scale before, mRNA vaccine technology is appealing for several reasons:

Molecular sequencing systems makes creation of mRNA almost as easy as writing a computer script.
Once sequenced, mRNA can be mass produced easily and cheaply.
There is no danger from viable pathogens in the vaccine production.
There are no infectious agents or toxins injected into the vaccine recipient.
Once the delivery system is perfected, vaccinations for many different pathogens can be created by simply altering the mRNA sequence, making it possible for vaccines to respond quickly to emerging viral variants.

Before we anoint mRNA vaccines as our pandemic savior, we should first listen to voices urging caution about this new technology. For example, in a recent New England Journal of Medicine publication, Dr. Mariana Castells and Dr. Elizabeth Phillips note that the incidence of anaphylaxis, a serious, sometimes fatal allergic reaction, associated with the Pfizer SARS-CoV-2 mRNA vaccine is “10 times as high as the incidence reported with all previous vaccines, at approximately 1 in 100,000, as compared 1 in 1,000,000.” Why? And moreover, what are our expectations of vaccination? Do vaccines prevent COVID or simply reduce COVID complications? How long will immunity last? Who should NOT get the vaccine? Answers to these and other questions are not readily apparent, not because of a failure of diligence, but because there has simply not been enough time to collect, compile and analyze the data that will eventually yield answers.

The Center for Evidence Based Practice at the University of Pennsylvania recently published a review of the adverse effects of mRNA vaccines. Among their findings are the following:

There are no specific guidelines for use of messenger RNA (mRNA) vaccines or contraindications to mRNA vaccines.
No large trials of any mRNA vaccine have been completed yet.
The only evidence on safety of mRNA vaccines comes from small phase I and phase II trials of SARS-CoV-2 vaccines, with follow-up typically less than two months.
Systemic adverse events such as fatigue, muscle aches, headache, and chills are common
The rate and severity of adverse events appears to be higher for the second dose of vaccine than for the first.
Higher vaccine doses appear to increase the rate and severity of adverse events.
Larger trials of SARS-CoV-2 vaccines are in progress, with results expected in mid-2021.
There is not sufficient evidence to support any conclusions on the comparative safety of different mRNA vaccines.
Direct evidence on the comparative safety of mRNA vaccines and other vaccines is lacking.

Clearly, mRNA vaccines offer an attractive, promising alternative to other vaccine technology, especially when a new vaccine is needed quickly. However, it is a new technology associated with risks of the unknown. Many unanswered questions remain, demanding a sober examination of the evidence for and against vaccine safety. Since the risk-to-benefit ratio from taking a COVID vaccine varies individually, I urge individual decisions, not collective ones. The Infectious Diseases Society of America recently published a comprehensive FAQ on vaccine safety which you may find to be a valuable great resource for making an individual decision.

Although paved with good intentions, the early path of new technologies is frequently littered with unintended consequences. Next time, I will tell a story of good intentions that ended tragically for many.

2021 COVID-19

The Latest about Variants

The CDC recently released new information about the variants of SARS-CoV-2, updating information previously released.

Although SARS-CoV-2 mutates frequently, about once every two weeks, most mutations do not result in a clinically different virus. However, three variants have emerged which are being watched closely.

B.1.1.7 is the first variant of concern which emerged in the UK last December and is now present in at least 70 countries, including the United States. This variant is associated with a fifty percent higher transmission rate, which means it may soon be the dominant form of the virus. There is emerging data that suggests this form of the virus is also associated with a higher death rate.

B.1.351 emerged in South Africa and has spread to other countries, including the United States. There is data that suggests that the Moderna mRNA-1273 vaccine currently used in the US may be less effective against this variant.

P.1 has been found in Japan and Brazil. As of late January, this variant is known to exist in the United States. There is data suggesting this variant may be less susceptible to immunity acquired either by previous infection or by vaccination.

All three variants are concerning because of mutations in the spike proteins in the virus. These proteins are significant because they are responsible for the binding of virus to cells in the back of the nose, the first step in infection. They are also significant because antibodies in the human immune system work by recognizing these spike proteins. Whether these antibodies come from natural immunity (i.e., previous infection), induced immunity (i.e., vaccination) or convalescent plasma, altered spike proteins may allow viral particles to slip past this line of protection.

Since we’ve talked a lot about vaccination recently, now may be the time to discuss how COVID vaccines work. We will pick up there next time.

2021 COVID-19

The Mask Clinic

Face coverings, N95 masks, respirators, and P99 masks—how do we make sense of this confusing alphabet soup?

Standard face coverings do not have a rating. They made from cloth or paper, and they usually resist fluids. But they leak. Air comes in around the sides–anyone who has worn a mask (and who hasn’t?) knows this. Nevertheless, mask usage is key to protecting you from exposure to SARS-CoV-2, the virus that causes COVID-19. However, there are more infectious organisms that require a rated mask for protection. One such organism is Mycobacterium tuberculosis, the organism that causes tuberculosis. Another such organisms may be the B.1.1.7 variant of SARS-CoV-2, the variant of concern, which has a transmission rate fifty percent greater than standard SARS-CoV-2.

Rated masks have a letter prefix, either N, R, or P, followed by a number, usually 95, 99 or 100. The letter refers to how resistant the mask is to oil, and the number refers to the percentage of airborne particles filtered by the mask.

Mask Type	Airborne Particles Filtered	Resistance to Oil
N95	At least 95%	No
N99	At least 99%	No
N100	At least 99.97%	No
R95	At least 95%	Somewhat
P95	At least 95%	Strong
P99	At least 99%	Strong
P100	At least 99.97%	Strong

These masks are held snuggly around the face by elastic bands or straps around the head that eliminate the gaps between the skin and the mask. Note that “KN95” masks do not meet U.S. standards, and often have bands that loop over the ears and not over the head. Don’t let the word “respirator” confuse you: respirator is just another name for a rated mask. All the masks in the table above are also known as respirators. For protection against most respiratory organisms, an “N” mask is adequate since resistance to oil is not necessary.

So what level of protection is needed? Standard face coverings are adequate protection against SARS-CoV-2 exposure if worn properly by all individuals interacting at distances less than six feet, but an N95 mask is needed to provide adequate respiratory protection against tuberculosis. At 2 microns long, tuberculosis organisms are much larger than SARS-CoV-2 particles which measure 0.1 microns or less. Still, I believe that N95 masks also provide adequate protection against COVID, even when unmasked, infected individuals are nearby because of the experience of collectors at the test collection centers run by the laboratories where I work. These collectors use an N95 mask and a face shield for respiratory protection, and none has become infected at work despite collecting thousands of positive swabs.

How does an N95 mask work? In addition to forming a tight seal on the face around mouth and nose, N95 masks are made from material with pore sizes between 0.1 and 0.3 microns in diameter.

“But wait!” you might say, “You said that a SARS-CoV-2 virus particle is 0.1 microns or less. What keeps the virus from slipping through?” The spread of SARS-CoV-2 virus is on respiratory droplets. These droplets are 5-10 microns in diameter, much larger than the pore size of the masks, keeping most viral particles out of the nose of the mask wearer.

What about the coming B.1.1.7 variant of SARS-CoV-2? I want to be very clear: the FDA does not recommend the general use of an N95 or higher rated mask for COVID-19 prevention. Although N95 masks protect against SARS-CoV-2, there continues to be supply shortages of these masks. Therefore, the FDA recommends that their use be reserved for health care providers. However, as we discussed last time, there may soon be a time that this recommendation changes. It is possible that an N95 mask will be required to protect against the B.1.1.7 variant because of its higher transmission rate.

So what other new information is there about the SARS-CoV-2 variants? We will discuss the latest information about variants next time.

2021 COVID-19 Testing

Where’s the Flu?

Since October, all rapid SARS-CoV-2 PCR tests performed at the hospital laboratories where I work have included a PCR test for flu. But of the thousands of tests performed, not one positive flu has been detected. Has COVID cured flu?

No, I don’t believe that COVID has cured the flu, but I believe that masks have dramatically reduced the prevalence of flu in the community. Flu is a respiratory infection, passed from person to person by the same transmission mode as COVID, mainly inhaled droplets from an infected person. Standard face coverings reduce flu transmission in two ways. First, droplets from an infected person are less likely to be spread into the surrounding air; instead, they hit the mask and fall. Second, the mask helps filter the air of droplets that may contain viral particles. The result is a reduction, but not an elimination, of respiratory viral transmission.

So why haven’t masks cured COVID? SARS-CoV-2 is more infectious than flu, meaning that compared to flu, far fewer SARS-CoV-2 viral particles are needed to cause infection. Masks reduce the number of viral particles in the air, but they don’t eliminate them. Some virus leaks out from the masks of infected persons, and some virus can be inhaled by masked individuals nearby. It’s a matter of how much virus gets inhaled. It takes much more flu to cause infection than SARS-CoV-2. Masks slow the spread of COVID-19, but do not eliminate disease the way masks have flu.

We may use this COVID/Flu comparison to make some predictions about the B.1.1.7 variant, the “variant of concern” now reported in at least 70 countries. This variant is reported to be much more infectious than the standard SARS-CoV-2 virus, about fifty percent more, with the consequence that masks may not be enough to slow its spread through the community. Tighter, less permeable, and more uncomfortable masks may be necessary to protect against this variant as it spreads across our nation. The higher transmission rate also predicts that this variant will soon be the dominant form of the SARS-CoV-2 virus in the U.S.

If standard face coverings may soon become less effective protection against COVID-19, maybe now is the time to learn about different types of masks. We will do that next time.

2021 COVID-19 Testing

New Information about Variants and Tests

Post author By Kevin Homer, MD
Post date January 20, 2021
1 Comment on New Information about Variants and Tests

On January 8, the FDA released a warning that certain PCR tests for SARS-CoV-2 available by EUA may have seriously reduced sensitivity for the SARS-CoV-2 Variant of Concern (VOC, also known as 20I/501Y.V1, VOC 202012/01, or B.1.1.7), resulting in false negative test results. The tests mentioned in this advisory are the Accula SARS-Cov-2 Test by Mesa Biotech, the TaqPath COVID-19 Combo Kit by Thermo Fisher Scientific, and the Linea COVID-19 Assay Kit by Applied DNA Sciences. How will this development impact testing?

The SARS-CoV-2 virus mutates regularly with new strains emerging once every two weeks. Mutations occur in the genetic material of the virus, the very material that molecular test methods like PCR use to detect the virus. Until recently, none of these mutations has been associated with different clinical characteristics, such as more severe disease or increased rate of transmission. However, a variant of concern (VOC) recently emerged in the UK. As far as we know, this is still the one and only VOC. Since this VOC has a much higher rate of infectivity than standard SARS-CoV-2 virus, we can expect it to spread quickly. It will probably soon become the predominant form of the virus in the United States.

PCR tests look for a match in a region of viral RNA. The target sequence is like a computer password: any mistake causes the password to fail, even if the entry is off by only one letter. Therefore, when a mutation occurs in the target region of a PCR test, the test will be unable to detect the virus. This is why the tests mentioned in the FDA warning may not detect all forms of the virus.

Most PCR tests look for a match in more than one target sequence of RNA. Generally, the more targets in a particular test system, the less likely a mutation will impact test results. But beware: negative results should be evaluated in combination with history and symptoms. If COVID-19 is still suspected after a negative test, consider repeat testing with a different test—one with different targets.

How do you know which test you received? Look closely in the fine print of the results—the test used is probably referenced there. If not, ask.

Although most commercially available tests will continue to detect the VOC, these tests do not identify whether the virus is the variant or standard form. They will only identify that a SARS-CoV-2 virus is present. Furthermore, there is no assurance that a variant will not emerge that evades detection.

Obviously, this is a situation we will continue to follow closely.

2021 COVID-19 Science

The FDA and Its EUAs

We have learned that science is a method, not a product. Science begins with an educated guess which is proven true by a series of experiments designed to show that the guess is false. If the hypothesis cannot be proven false, it is accepted as true by the community of scientists. Now that we’ve waded up to our armpits in philosophy of science, let’s move back into shallow waters and consider the process by which our FDA approves new drugs, medical devices, and laboratory tests in the United States.

First, I am going to reveal a personal bias. I believe that the United States has the safest healthcare system in the world for individual patients. Notice I did not say most efficient, cost effective, or optimized for populations. But if I am sick or injured, I want my healthcare delivered by U.S. trained doctors in U.S. hospitals using drugs, devices and tests approved by the U.S. FDA.

The FDA has been disparaged for being too slow to approve new therapies and methods. True enough, the FDA’s priority is not speed. Instead, the FDA’s mandate is safety. The FDA conducts a thorough, time-consuming review of all details of science supporting an application for approval, granting approval only after all questions have been answered satisfactorily. The FDA conducts post-market surveillance of approved drugs, devices and tests, mandating reporting of adverse outcomes. The FDA’s slow, methodical pace keeps Americans safe.

The FDA does not conduct science. Rather, the FDA performs quality control for science, validating the logic, analytics and data supporting the claims of products submitted for approval. Therefore, FDA approval implies a level of trustworthiness akin to science. But like science, FDA approval takes time. Time is something we do not have in a pandemic.

Enter the Emergency Use Authorization, known as EUA. When time is short, the FDA may allow unapproved medical products to be used to diagnose, treat, or prevent serious or life-threatening diseases or conditions when there are no adequate, approved, and available alternatives. All SARS-CoV-2 tests have been made available by EUA. Convalescent plasma is transfused under EUA. Antibody treatments for COVID-19 are prescribed under EUA. Remdesivir, Baricitinib and the their combination are first line treatments for severe COVID-19, available for use by EUA. And COVID-19 vaccines released by Pfizer and Moderna have been made available by EUA. None have been approved by the FDA. The trust conferred by FDA approval should not be transferred to the tests, treatments, or vaccines we are using in the fight against COVID-19.

Are there reasons to believe that the vaccines are safe and effective? Yes, and good ones too. But as with any experimental treatment or product, risks of adverse outcomes are elevated. Individuals must evaluate whether the risks–both known and unknown–are outweighed by the potential benefits of the vaccine. In a recent article published in the New England Journal of Medicine, Dr. Mariana Castells and Dr. Elizabeth Phillips articulately summarize the outstanding questions about the vaccines currently available:

“In the world of Covid-19 and vaccines, many questions remain. What are the correlates of protective immunity after natural infection or vaccination? How long will immunity last? Will widespread immunity limit the spread of the virus in the population? Which component of the vaccine is responsible for allergic reactions? Are some vaccines less likely than others to cause IgE- and non-IgE–mediated reactions? Careful vaccine-safety surveillance over time, paired with elucidation of mechanisms of adverse events across different SARS-CoV-2 vaccine platforms, will be needed to inform a strategic and systematic approach to vaccine safety.”

Some may criticize me for suggesting that the vaccine is not risk-free and that it may be better for some to wait before receiving their shot. However, honesty is one of the foundational characteristics of science. We must be willing to follow the data where it leads, even if it leads to a place we do not want to go. It is dishonest to say that any COVID-19 vaccine has FDA approval; to say that possible adverse effects—short term and long term–have been fully evaluated by the scientific method; to say that the protective immunity imparted by vaccine has been fully studied scientifically; to say that vaccine will alter the course of the pandemic or any infected person’s disease. I am not saying the vaccines will cause harm, but likewise we cannot say the vaccines will not cause harm.

The vaccines available now are associated with the risks of the unknown. For some that risk is worth taking; for others it is not. Whether you decide to take the vaccine or to wait, keep doing what we know slows the spread of disease: mask up, keep apart, and isolate when exposed.

2021 COVID-19 Science Vaccine

The Science of COVID

Spoiler alert: This essay contains an unpopular conclusion, and you may disagree. It’s okay if you do, because you’ll probably be in the company of many of my colleagues who disagree with me too. Today I’m going to talk about when we can trust science. To do that, I’m going to pretend to be a scientist and a philosopher. This is dangerous because, as I have said before, I am neither a scientist nor a philosopher. Instead, I am a practitioner, applying science to the problems of diagnostic medicine. As a practitioner, I must know when science is applicable and when it is not. I know just enough about science and philosophy to be dangerous.

Our experience tells us to trust science, and the explosion of technology during our lifetimes tells us we can. But science is a process, not a product. Not everything labelled as science is science. To understand the difference, let’s consider how science works.

The scientific method begins with a hypothesis. A hypothesis is just an educated guess about some aspect of reality. It is proposed by a scientist as a fact of the world, something that can be relied on to be always true within certain conditions. If the conditions are true, the hypothesis can be used to predict the future and tell us about the past.

Once formed, the hypothesis is communicated to other scientists, who test the hypothesis by experiment. The objective of an experiment is not to prove the hypothesis true; rather, the objective of an experiment is to prove the hypothesis false. If successfully proven false, the hypothesis is rejected. This is the fate of most hypotheses. The path of science is littered by the half-truths of discarded hypotheses. On the other hand, if the hypothesis survives the challenges of repeated experimentation, it becomes elevated by the community of scientists to the status of theory, and its predictions become part of scientific knowledge. This is a relatively rare phenomenon.

The falsification objective of the scientific method is a commonly misunderstood aspect of the process, but it is fundamentally important. It gives science its power over other means of understanding reality, but it also gives science its pace. It takes time to test hypotheses. The proof of a hypothesis can be shortened by increasing the number of simultaneous experiments, but only to a point. Science, like fine wine, requires adequate aging.

For all its power, the elevation of hypothesis to theory illustrates another weakness of the method: theories are created by scientists. Scientists are people, and people make mistakes. Scientists have made many. We can review examples of the most spectacular blunders of scientists later. The point is that the mistakes of science are the mistakes of people, not fallacies in the method.

So why do we trust science? Because, despite its flaws and weaknesses, science has increased our understanding of the world exponentially. But can we be misled by science? Of course we can, and we are most vulnerable when products labeled as science are not developed with strict adherence to the scientific method.

This brings us to the controversial part. Most of everything we have learned and developed in the war against COVID-19, including the tests, the treatments, and the vaccines, should not be trusted as science. In the middle of this emergency, there has not been enough time to fully study the virus and the disease by the scientific method. Rather, what we have so far are merely hypotheses: the best guesses of the smartest and brightest people in the land. To be sure, these hypotheses are our best hope in this fight against pandemic, but they should not be labeled science. There has not been strict adherence to the scientific method. So, what should we trust, what should we view skeptically, and how can we tell the difference? We will address these questions next time.

2020 COVID-19 Testing

Spread and Detection of Variants

Post author By Kevin Homer, MD
Post date December 31, 2020
No Comments on Spread and Detection of Variants

Last time we learned that a new strain of the SARS-CoV-2 virus has emerged in London and southeast England. This variant strain, called “VOC 202012/01” or “B.1.1.7” is more infectious than the standard SARS-CoV-2. It has quickly spread to other parts of Europe, and its presence is now reported in Canada and the United States. At least two other distinct variants are reported in South Africa and Nigeria. How do we keep track of these variants, and what does their rapid spread mean?

The variants are named by adding suffixes of letters and numbers to help keep the many cataloged mutations straight. Two different systems may be used. For example, the South African variant is labeled “501Y.V2”, but it is also known as “B.1.351”. The Nigerian variant is called as “B.1.207”. Neither of these has been labeled a “variant of concern”.

A “variant of concern” is a strain is associated with differing clinical features such as greater disease severity or faster spread. “Variants of concern” will have the letters “VOC” in their name. So far, the first and only “variant of concern” is VOC 202012/01, the variant identified in London which has now spread into Europe, Canada, and the United States.

While none of the variants identified so far seem to evade detection by the PCR tests generally available to the public, these tests will not tell you whether a detected virus is one of the variants. Specialized sequencing is required to identify a virus as a variant. This testing is conducted on a regular but limited basis by the CDC, state and local health departments, and various universities.

The CDC is watching the evolution of variants closely. The concern is that increasing numbers of variants may change the way the virus spreads, may reduce detection by current tests, may create resistance to drugs such as monoclonal antibodies, or may produce a strain that evades immunity caused by vaccine or previous infection. We will watch too. As the “variant of concern” spreads into the United States, remember what keeps us safe: mask up, keep apart, and isolate when exposed.

2020 COVID-19 Testing

Viral Variant

A new variant of the SARS-CoV-2 virus is emerging in Great Britain, becoming the dominate form of the virus that causes COVID-19 in London and southeast England. What are the implications of this new variant?

The new variant has been officially named “SARS-CoV-2 VOC 202012/01.” You may also see it referred to as “B.1.1.7”, or “SARS-CoV-2 Variant” in both the popular and scientific press. This variant has a mutation in one of the spike proteins which binds the virus to human cells during the infection process. So far, this variant has not been reported in the United States.

Viral mutations are common. In fact, many different strains of the SARS-CoV-2 virus are likely to exist in the United States right now. But so far, none of these mutations has caused a significant difference in the binding capacity of the virus to human cells. At least none that we know of. Our understanding of SARS-CoV-2 continues to evolve rapidly.

The variant identified in England seems to spread more quickly in humans. The thought is that the change in spike binding protein makes it more likely for the virus to stick to human cells.

Why does increased stickiness of virus affect the virus’ ability to spread? After the virus sticks to the cells lining the inside of the nose and upper airways, the virus injects its genetic material into the human cell. This genetic material is programmed to take over the machinery of the cell, causing it to abandon its usual functions and become a virus producing factory, spewing out hundreds of new copies of the virus. These new viral copies infect other cells, either in the same body, or in bodies nearby. This accounts for the waxing of disease within a sick, infected person, and the spread of virus from person-to-person. If the virus is stickier, more human cells are taken over, and more copies of the virus are produced, making it easier for the virus to go, well, viral!

Will tests detect this new virus strain? Yes, PCR tests will, at least for now. Because PCR tests use two or three different detection targets, the change in this variant’s genetic code is not enough to evade detection by PCR tests. However, as the genetic code of the virus continues to evolve, it is conceivable that a mutation will arise that is not detected by tests currently in use, even PCR tests. Antigen tests, which already have low sensitivity, do not share the multi-targeted feature of PCR tests; therefore, even more false negative antigen test results can be expected when the variant becomes more prevalent.

Will the variant reduce the effectiveness of vaccine? The honest answer is that we really don’t know. Theoretically, this variant will not, since the vaccines released in the U.S. are polyclonal, causing the formation of antibodies to several different parts of the virus’ spike proteins. The theory is that even if one part of the spike protein changes, the antibodies will still be effective against the other parts that have not changed. But theory and reality are not the same thing. We won’t know for sure until vaccine effectiveness has been studied in populations infected by the variant.

This brings us to one final point about this viral variant. This variant is undoubtedly the first of many variants to come, and the answers for these yet-to-be-seen variants may be different than the answers for this one. Viruses want to survive. Just as the use of antibiotics causes the emergence of antibiotic resistance in bacteria, the use of vaccine will favor viral mutations that evade vaccine-induced immunity. Variants will emerge that are unaffected by vaccine.

The pandemic is a war, both metaphorically and really. Our best defense is the practice of what we know reduces spread: mask up, keep apart, and isolate when exposed. We will prevail. But it’s still too early to celebrate victory.

2020 COVID-19

Mask Up!

Individuals exposed to someone infected by SARS-CoV-2 should be quarantined to slow the spread of COVID-19 and keep our loved ones safe. However, being quarantined is a lot like being in jail. How can we avoid drawing this card?

We have learned a lot about the spread of SARS-CoV-2 in the last ten months. Those exposed to individuals infected by the virus are at risk of becoming infected themselves. According to the CDC, an exposure is an encounter of less than 6 feet apart and more than 15 minutes long when one or both individuals are not wearing face masks. By this definition, wearing a mask and keeping your distance from those not wearing masks prevents exposure to SARS-CoV-2.

Does that mean that you will never get SARS-CoV-2 if you wear a mask? No, wearing a mask cannot prevent all SARS-CoV-2 infections, but it will dramatically reduce your risk of infection and your risk of being dragged into quarantine jail.

How do we know that masks work? The CDC has published evidence for the effectiveness of masks. To this list, I add two observations from my own experience.

In the hospitals where I work, all physicians, staff, patients, and visitors are required to wear masks. Although some individuals have become infected with SARS-CoV-2 during the pandemic, contact tracing demonstrates that individuals were infected outside of work. I have not observed “hot-spots” of infection in clinical areas where these precautions are practiced. This, despite treatment of hundreds of patients with COVID-19 at these hospitals.

The second point is the absence of flu in Texas this December. By this time of the year, flu season is generally in full swing. In mid-December, the laboratories where I work have usually detected many positive flu samples. However, this year these same laboratories have yet to see their first positive flu test. This is not for lack of testing for flu. Since October, every rapid PCR test for SARS-CoV-2 has included a test for flu.

Why is this observation relevant? Flu is a respiratory illness transmitted in much the same way as SARS-CoV-2. What prevents spread of coronavirus also prevents the spread of influenza virus. With masking orders in place, the spread of flu has dramatically reduced.

If masking has effectively stopped the spread of flu, why is COVID-19 surging? Coronavirus is much more infectious than flu. The point is that masking reduces all disease that spread by the airborne route. Imagine what the surge would be like without masking?

In Texas, we love to wear our boots and hats. This year, we’ve learned to love our masks, worn all the way up, covering the nose and mouth. Be safe during the coming holidays. Mask up, y’all!

Share this:

Share this:

Share this:

Share this:

Share this:

Share this:

Share this:

Share this:

Share this:

Share this: