This commentary is by Dr. Turner Osler, a career academic trauma surgeon at the University of Vermont Medical Center turned research epidemiologist.
Our pandemic is now being driven by a new virus, Delta, which is far more transmissible and has thus replaced the original Covid virus (now retrospectively named Alpha). The reason Delta has exploded is simply because it reproduces on a vastly more lavish scale than did Alpha; each Delta virus produces 1,000 times more offspring than Alpha.
In other respects, Delta is much like Alpha, although sore throat, headache and runny nose seem to be more common with Delta; loss of smell remains a signature symptom of both Alpha and Delta.
But it is the heightened transmissibility of Delta that is a game changer.
Because the pandemic has put a much more advanced version of the Covid virus into the game, our tactics must also change. For example, while vaccination provided an adequate protection against possible breakthrough infections caused by Alpha, unfortunately this isn’t true for Delta. The good news is that the vaccinated are still largely protected against hospitalization and death. But even if survival is assured, being ill with Delta can be a very unpleasant way to spend a week. And, it’s not clear how often long-haul syndrome will follow a breakthrough Delta infection.
For the unvaccinated, Delta is a far graver risk: Not only is infection with the Delta much more likely to occur, but the risks of hospitalization and death are just as substantial as with the earlier Alpha virus. So, the bottom line for both the vaccinated and the unvaccinated: Don’t become infected with Delta.
How to avoid infection? Well, being vaccinated yourself is the obvious first step. While you are still vulnerable to breakthrough infections, you are less likely to become infected, and far, far less likely to be hospitalized or die.
Perhaps less obviously, being surrounded by people who have been vaccinated provides a second layer of protection. You’re safer if your family and others in your bubble are vaccinated; moving to a state and community where vaccination rates are high expands this protection, though this is a bridge too far for most. But if you can somehow arrange for your neighbors to be less likely to shed virus, you are simply less likely to encounter the virus.
It’s harder to protect those unable or unwilling to be vaccinated, so for this group the tools other than vaccination — such as social distancing and masking — become much more critical. Masking in particular is critical, because it remains the single best technology to keep virus particles out of one’s respiratory passages. And, because the Delta virus reproduces so much more prolifically, better masks worn better are now required if masking is to work.
What do I mean by “better masks”?
I spent decades wearing surgical masks as a professor of surgery at the University of Vermont, so I’ve thought a lot about why surgeons wear masks, and it comes down to this: Surgeons wear masks to protect their patients.
With the discovery in the mid-1800s that bacteria caused surgical wound infections. a number of measures became standard: sterile instruments, elaborate hand washing, surgical gloves, and by the late 1800s a surgical mask was added to control droplets of saliva (or drops of sweat; it can be hot in an operating room) that might travel from a surgeon into the patient’s wound.
Originally these masks were simply layers of gauze held over “the nose, mouth and beard” by strings. It took decades, but by 1935 masks had become a standard part of surgical attire; indeed, the mask came to be the defining piece of surgical attire. Over time, surgical masks became a manufactured, disposable part of surgical kits and these newer masks were water-repellent, providing some measure of protection for surgeons against splashes.
Crucially, however, surgical masks were never designed or intended to protect the wearer. An entirely separate technology to protect the wearer from rock dust was developed in the 1970s for use in mines where silicosis posed serious health risks for miners.
Although these respirators superficially resembled surgical masks, the technology was entirely different and much more advanced, capitalizing on melt-blown materials and the ability to use static charge to ensnare very fine particles. These respirators remove over 95% of particles as small as 0.3 microns. Additionally, the shape of the mask allows for an airtight seal with the face, preventing dangerous leaks that allow unfiltered air to enter the nose and lungs.
This technology was ultimately adopted by the medical community, and by the mid 1990s these masks became standard for controlling viral aerosols, and are still the masks used today by workers in ICUs caring for Covid patients.
If standard surgical masks provide so little protection compared to N95 respirators, why are so many people still wearing surgical masks? Simply put: Surgical masks are far more available, far less expensive, and far better than nothing.
The advent of Delta has changed this calculus, however. While simple surgical masks remove some of a viral load, the viral loads from Delta can overwhelm the protection these simple masks offer. N95 respirators are now essential, especially for the unvaccinated, whom the Delta virus puts at far higher risk of infection and possibly tragic outcomes.
At the end of the day, if you’re putting up with a mask, you should get the most out of it that you possibly can, and wearing a carefully fitted N95 mask provides by far the best protection. And, by keeping yourself safe from infection, you will be protecting those around you as well. Now there’s a bargain.
