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COVID-19 One Year Later: PILots, Aviation and Everyone Else

Exactly one year ago I wrote about my early impressions of the evolving COVID epidemic that was bound to have a huge impact on pretty much everything in our daily existence, not the least of which was aviation and pilots. 

March was also the one-year anniversary of the international declaration warning of a true COVID pandemic.  Along with everyone else, it sure hit us hard but I'm optimistic that things with aviation and the rest of the world will return to normal some day.  One thing that should help air travel and pilot hiring rebound is that COVID spread on commercial flights is certainly possible but not more than average activities.  Even with everyone breathing and then re-breathing the same air in a closed cabin, the risk of infection is pretty small according to a recent Department of Defense study.  That's because of almost universal use of HEPA filters (high efficiency particulate air filter) in air circulation systems. However, none of this helps us in the GA world.  With open cockpits, no filter systems, and non-pressurized cabins we breathe the same air as everyone else in our airplane, more on this to follow.

There's another issue that will affect all pilots and that's the potential sequelae of the virus that the NIH is calling, "long COVID."  It's a constellation of debilitating symptoms that the CDC reports affects upwards of 35% of post-viral patients and we really don't yet know how long it can linger.  We do know that it can have significant long-term negative effects on neurological, pulmonary and other physiological functions.  There is also good data to suggest post COVID illness causes "brain fog" that I wrote about a while back and it all adds up to big potential risks for pilots who suffer from this new illness.  Unfortunately, there's not always a great correlation between the severity of the initial symptoms and development of long-term symptoms.  Just this week the FAA released their new COVID guidelines for Aviation Medial Examiners.  AME's are going to have to customize their examination based on these possible long-term side effects and the FAA guidelines provide for just that with re-issuance on a tiered basis.  Further pulmonary and cognitive testing will only be required where the AME believes there are lingering effects of the virus. It makes good sense and we'll see how it works. AOPA president Mark Baker, Chairman Dr. Ian Fries, myself and the other members of the AOPA's Board of Aviation Medical Advisors were able to meet with the FAA's Federal Air Surgeon Dr. Susan Northrup and talked about setting up a COVID advisory panel. To their credit, the FAA has been very receptive to our ideas and input. I'll have more to say on this topic in an upcoming article.

Calamities like COIVD always bring out the best in some and there is no shortage of heroes of the COVID-19 pandemic. David McCullough wrote a great book called "The Pioneers" about a guy named Ephraim Cutler who kept a diary about his travels and the brave men and women who were his fellow pioneers. "The character ought to be known of these bold pioneers.  From whence did they spring?   For what causes, under what circumstances, and for what objects were such difficulties met and overcome?" That applies just as well today as it did way back then.  There are lots of heroes.   Among these heroes were air evacuation pilots and crews and also some GA pilots who volunteered fly medical supplies and at their own risk to transport COVID patients for medical care.  More heroic actions were clearly taken by the nurses and healthcare workers who cared for sick patients especially early on before the exact risks were known. Many had inadequate personal protection equipment (PPE) and still spent entire days caring for sick and dying patients.  CDC statistics show that it took a tremendous toll in illness, death and psychological depression among healthcare professionals.  It's hard to know exactly how many medical professionals died but there were several thousand and most were younger than the average COVID patients.  The head nurse in one of the COVID ICU's I worked in got the virus early on and spent more than a week on a ventilator in her own ICU cared for by her coworkers.  She fortunately made a full recovery and is now back at work in the same ICU taking care of other COVID patients in the same bed she occupied.  She is one of the true heroes and  "bold pioneers." There are hundreds and thousands of similar stories. 

Another group of heroes are all the scientists who developed the COVID vaccine that has proven to be so effective.  Inventing, safety testing and bringing to the public a vaccine for a virus in 8 months is an historic accomplishment that is almost unimaginable.  Consider the fact that the AIDS virus that can be found in DNA samples from over a 100 years ago, has been a world wide epidemic for more than 40 years, and there's still no vaccine for it.  There are lots of reasons that it usually takes years to develop vaccines.  It's not only an issue of the safety of the vaccine as much as it has to do with the costs.  It sure helped that the government stepped in early on providing funds that allowed the research to progress and testing to start quickly without financial risk. Physician-scientist Margaret Liu said, "this was accomplished by the sheer volume of resources" that went into development." She's right.

The efficacy and safety of the vaccine is pretty clear.  There are 4 current vaccines and all are in the range of 95% effective at preventing serious infection, hospitalization and death and that's something of a miracle.  There also have been very few serious complications besides some minor side effects and injection site pain but allergies to everything can exist so everyone should heed their doctor's advice.  The incidence of even the most minor complications is less than 2-3% according to the HHS vaccine adverse event reporting system (VAERS) and any deaths even remotely around the time of the shots is reported to be miniscule (0.0018%).  Still, it's your body so it is your choice. I personally have gotten two doses and have nothing but a little ache in my left arm for a few hours and total confidence in my safety to tell about it. 

I get a lot of questions from patients and fellow pilots with concerns about the vaccines and if they were rushed into use and not adequately tested.  The only novelty of the vaccine is how it gets into our cells to do its work.  The vaccines are made of little fat bubbles with a tiny strand of messenger RNA (m-RNA) particle enclosed.  This fat capsule that the messenger is contained in is what's new and was truly perfected at "warp speed."  The fat bubble sticks to our own cells where it is readily absorbed and lets the vaccine messenger enter the cells.  This is called a "lipid nanoparticle vector" and protects against degradation of the messenger by our immune system until it can do its job.  The FDA originally approved it about 5 years ago.  The other part of the shot is the m-RNA and there's nothing new about m-RNA vaccine technology.  It's been around since the late 1980's and is as simple as it is brilliant.  Our body is filled with zillions of messenger RNA particles that turn on various portions of our DNA to make all the chemicals that run our lives.  This messenger tells our DNA to make the same protein that is on the outside of the Coronavirus capsule (the "spike" protein).  That's the part of the virus that sticks to our cells (kind of like the vaccine fat bubble) and lets the virus enter our cells where it replicates itself leading to COVID infection. 

The vaccine tells our own bodies to make our own "spike protein" and when our immune system sees that protein it triggers a widespread response leading to production of antibodies to it.  Then, if our body sees the protein again (infection by the virus) we are armed with those antibodies and ready to kill the virus.  Without pre-arming our immune system you can get pretty sick, as we've seen tragically so many times already.  Another good thing about the vaccines is that they trigger both short and long-term antibody protection.  One form of immunity we develop is something called "Memory T-cells" that are in our blood and respiratory tract and that's all good to have in an airplane or anywhere else.  It probably lasts forever, a Vanderbilt University study collected blood samples from numerous 90 year olds who were exposed as children during the 1910's to the Spanish Flu virus (also a coronavirus).  Even after almost a century, their T-cells still mounted a vigorous antibody defense when re-exposed to the virus (in the lab of course).

There are mutational variants with this virus as expected with all viruses but thanks to some great work by virologists and scientists like Dr. Dave Ho these mutations have already been mapped out.  According to recent studies published in the New England Journal of Medicine, the vaccines now in use are equally effective against virtually all of the variants out there except for the South African gene mutation.  The current vaccines appear to be a little less effective against this variant but CDC data shows they are still useful in the range of 55-75% protection and that's still pretty good.  Scientists report that it's a relatively simple matter to tweak the vaccine to keep up effectiveness for these mutational changes so it's likely we'll get a yearly COVID "booster" shot like a yearly flu shot to keep up with these changes. 

I also get a lot of questions regarding the infectivity and testing for the virus.  It's really unusual in disease management that a positive test result is the sole criterion for a diagnosis but that's the case with COVID-19. Normally when you're sick, docs use tests to support a clinical diagnosis not as a substitute for it. That means that even with a positive test, it's not clear who is actually sick and who isn't. The most common test is the PCR (polymerase chain reaction) test and results can be hard to interpret and easily manipulated. You can only spread the infection when you have live virus in your system.  Since the PCR test picks up any tiny fragment of viral RNA, alive or not, and then multiplies it over and over again until it can be "seen" there are lots of inaccurate results that are either clinically insignificant or outright false.  The FDA has cautioned that anywhere from 20 to 70% of tests may be wrong or just clinically irrelevant due to this technology. There is very little correlation between nasal swab PCR tests and live viral culture tests so you can be PCR positive for months but not sick or infectious.  Just "testing positive" has little bearing on illness and spread of COVID. So just getting a quick PCR nasal swab before someone flies on an airplane is not particularly helpful.  Interpreting these data has also generated issues with COVID mortality statistics reporting. There's a huge difference between dying with a COVID positive PCR and dying of COVID illness so the real mortality of the disease is hard to figure out. The best guide to true mortality statistics are in the CDC reports on "excessive deaths over expected" data that shows several large spikes over the normal range.  Unfortunately a large number of our fellow citizens have died this year, whether it's "with" or "of" COVID.   For sure it's a lot more than during the average flu season.

The mechanism of the illness is better known with a year of experience.  The virus triggers a huge inflammatory reaction that we call "SIRS" (systemic inflammatory reaction syndrome) that overwhelms and poisons the body's systems.  The worst end organ affected is usually the lungs that explain why spread is by live viral particle from airway track droplets. As I said above, live virus is the only way to spread the disease and patients generally have transmissible disease mostly when they are symptomatic from the virus, when you feel like you have "the flu."   That's about a 7-10 day window after infection has occurred.  That's really important and tells us that if you feel sick stay home.  Self-isolation is one of the important ways to interrupt the spread of this disease.  It's also important for us GA pilots to help protect ourselves.   Make sure everyone on your plane is symptom free at flight time and has been for a week or so before. The data on asymptomatic spread is still being sorted out but as documented in a recent British Medical Journal review and even within households transmission between family members is low when there is no clear flu-like symptoms.

Another important issue for us all, especially in the GA world, is whether or not masks and "social distancing" are protective. You sure can't social distance in your C-172 but what about those masks?  Theoretically a mask should help as breathing in the virus spreads the disease.  But peer reviewed medical data on masks do not really show as much protection as might be expected. There are two reasons, the first is you can not only get infected by breathing in live virus that hang in the air but also from those droplets that eventually fall out of the air at a rate depending on the weight, most within about 6 feet (sound familiar?). Masks are not very comfortable and lead to a risk of contaminating yourself by getting the particle droplets on your hands and them putting them on your face with repeated adjustments of masks. The second reason is about the kinds of masks like cloth ones that don't block anything. As recently as February 2021 a review from Swiss Policy Research cited ten peer-reviewed medical articles showing little value in public use of most masks.  The issue with surgical masks is that they only redirect the air you inhale and exhale to the sides.  If someone who is actively shedding virus coughs or sneezes near you, small droplets will hang in the air for a while and you can still breathe them in, just around the sides of the mask.   "Social distancing," being outside or staying out of the range of these droplet inside, is probably the best protection for you from an infection and I think that's here to stay.

With all that said, some masks will definitely help.  The CDC documented has that true air filters like the N95 and PAPR (powered air-purifying respirator) masks will prevent you from inhaling viral particles. In order to be effective filters, these masks must seal around your nose and mouth so no air escapes around the perimeter and most are custom fit to function as true barriers to inhaled disease. This is a totally different technology from cloth or surgical masks and what I wear around actively infective COVID patients. But they are neither readily available nor recommended for common use in the community.  This type of mask is also pretty ungainly, uncomfortable, and sometimes even hard to breathe through. Using these masks in the cockpit at altitude and trying to communicate through a thick filtering mask to ATC is pretty hard. There have been some recent reports documenting errors in aviation communication both on the ATC side and transmissions from the cockpit with mask mandates in place.  Pilots need to take that seriously and make sure you're read backs and hear backs are accurate.  Also, be on the lookout for fake N95 masks that don't protect you at all.  There are so many of these counterfeit masks now that the CDC publishes guidelines so you know if you're getting cheated.

Putting all this together what we've learned in a year are many important things about the virus and staying healthy in the cockpit and right here on the ground.  (1) Get the vaccine when it's offered, it works and it's safe. (2) Wear a mask if it makes you feel better BUT keep your hands off it and away from your face and change the mask at least every day. (3) Realize masks don't do much as filters for air you breathe but they do remind everyone to stay farther apart from each other and social distancing does help. (4) Stay home if you feel sick because you probably are.  When you have symptoms you have live virus in your system, and that's the most likely time you will pass this illness on to someone else. (5) Don't fly anyone in your plane who is sick or has been recently. (6) When you are in public places keep your hands off high touch surfaces like handrails and door knobs, live virus can hang around on those surfaces for a while, wash your hands a lot, then re-read #2 above.  My conclusion last year was that this is a serious disease and that's sure true.  This has been a horrific flu season.  Take COVID very seriously, but as I said last year, we can deal with this and there's no need to panic.  Fly safe and stay safe.

Kenneth Stahl, MD, FACS

Kenneth Stahl, MD, FACS is an expert in adapting principles of aviation safety to the healthcare industry for patient safety. He also writes and teaches pilot safety principles and error avoidance. He is triple board-certified in cardiac surgery, trauma surgery, surgical critical care and general surgery and holds an active ATP certification and a 20-year member of the AOPA. Dr. Stahl practices surgery full-time and is Healthcare Division President for Convergent Performance, an industry leader in teamwork, checklist and accountability training and consulting. He can be reached at [email protected]

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