As the science around COVID-19 evolves, our “prevention” methods aren’t

Evidence-based policies are no match for bureaucratic inertia.

Photo by Vera Davidova on Unsplash

“Test and trace.” “Socially distance.” “Wear a mask.” “Sanitize surfaces often.” “Wash your hands.”

These are all sentiments that have persisted since the beginning of the COVID-19 pandemic, and many of these recommendations existed based on a single disastrous assumption: SARS-CoV-2 is primarily spread through fomites and large droplets.

It’s difficult to ascertain where exactly this assumption came from, and why it’s persisted as long as it has — while more recent lab-based studies have strongly suggested COVID is spread through small aerosols and NOT large droplets, real-world observations should have made this abundantly clear well before then. Outbreaks were almost always tied to indoor, poorly-ventilated spaces, while outdoor transmission was exceedingly rare. The infectiousness of SARS-CoV-2 suggests aerosolized transmission as well, as mechanistically it would be more difficult for someone to spread the virus to several other people at once through droplets alone.

Yet here we are, 18 months later, still obsessively sanitizing surfaces, standing on six-foot-distanced dots and donning loose-fitting, porous cotton masks while talking to the grocery clerk through a two foot wide pane of plexiglass.

Why are we still doing it?


Many can remember the fomite obsession early in the pandemic — hand sanitizer shortages, wearing gloves everywhere, letting mail sit out for days before bringing it into the house, sanitizing groceries. After all, the prevailing narrative was “sanitize surfaces”, “don’t touch your face”, etc. There was some early scientific evidence to support these measures, as studies found SARS-CoV-2 could last on stainless steel for days.

However, these studies did not reflect real-world conditions. In another study, ordinary surfaces were swabbed for SARS-CoV-2 in areas where COVID patients were quarantined. Viral RNA was found on about half of them but all of the samples were uncultivable — meaning it could not feasibly infect someone.

Despite this evidence, obsessive sanitation is still very common today. This isn’t without harm, either. It gives a false sense of security, and constantly sterilizing one’s surroundings could actually kill off bacteria that are critical for human health.

Social Distancing

One year ago, over 200 scientists signed a letter warning the WHO that COVID was an airborne threat, calling for improvements to ventilation and other adjustments to public health recommendations to align with the idea that SARS-CoV-2 particles will not fall in a predictable 6 foot arc as initially thought. Much of the prevailing public health guidance was created based on this assumption — that if we keep our distance and wear masks, the large droplets produced from breathing, sneezing and coughing would only travel about 6 feet before gravity did its job to bring the virus harmlessly to the ground — or less, if masks were involved.

However, with tiny aerosols, this is not the case. Most people can recall seeing dust particles seemingly “floating” through the air by a window when the light hits it just right. These particles are typically dozens of microns, yet still take quite a while to fall to the ground. Unsurprisingly, tiny aerosols under a micron also can take a very long time to fall — courtesy of Stokes’ Law, we can estimate roughly how long it takes for a COVID aerosol to fall to the ground in still air:

Table of Stokes’ Law calculations courtesy of Stephen Petty

Almost all breath particles have been found to be under 1 micron, so according to Stokes’ Law COVID particles can remain suspended in air from hours to days. This suggests distancing rules have largely done nothing as COVID particles can remain suspended in air for hours, and get carried dozens of feet by the slightest movement of air. This isn’t a fringe conspiracy theory, either — MIT research has suggested as much.


Naturally, if SARS-CoV-2 is airborne, the effectiveness of porous, loose-fitting cotton masks should be in doubt. “Air” will take the path of least resistance. It will still go through or around the mask and fill a poorly-ventilated, indoor space.

Many would likely respond “But, what about the dozens of studies that show that masks are effective?” These studies mostly fall under 4 categories:

1) Mathematical models that by design must assume masks are effective to “prove” masks are effective. One recent model-based study made the ridiculous assumption masks reduce infectivity by 50%, which is a number that hasn’t even come close to being attained in real-world trials.

2) Glorified anecdotes such as the infamous CDC hairdresser study that found infected but masked hairdressers did not pass the virus on to any of their customers — but by its own admission did not test over half of the exposed customers during follow-up.

3) Studies that use real-world data but have arbitrary endpoints to try to prove their hypothesis — for example the Kansas mask study that claimed masks caused a decline in cases for counties that mandated masks during low community transmission. The study failed to mention both masked and unmasked counties had massive and equivalent spikes after the end of the study, which completely nullifies its conclusion.

What happened in Kansas mask/non-mask counties after the CDC study’s conclusion.

4) Lab-based mechanistic studies that either measure particles that could not feasibly infect someone or assume a perfect mask fit on someone’s face which is never the case in real world scenarios. An example is the “double mask” study from the CDC that measured particles between 0.1 to 7 microns despite an overwhelming majority of respiratory particles being well under one micron.

None of this is quality evidence. Beyond the mechanistic impossibility of masks stopping such radically behaving particles, a study published just recently in the International Research Journal of Public Health found mask mandates and compliance were not associated with reduced COVID-19 spread in the United States. Unlike the other aforementioned studies with arbitrary endpoints, this one covered the entire fall and winter wave.

Additionally, the sole peer-reviewed randomized controlled trial conducted regarding masking and COVID-19 found absolutely no benefit for the masking group. For those that aren’t familiar, RCTs are a gold standard method to measure the effectiveness of a medical intervention.

Speaking of RCTs, in 2019 a meta-analysis conducted by the WHO found the 10 best RCTs regarding masking and influenza. None of these studies — zero — could find a reduction of illness in the mask group compared to the control. While there are many ways that influenza is different from COVID it’s generally thought to be in the same particulate size range as COVID-19. In other words, the mode of transmission is likely also primarily through aerosols.

Yet here we are, in September of 2021, and masks are still the last thing to go when COVID numbers decline and the first thing to come back when numbers start rising again.

Alternative solutions

Let’s provide proper guidance on risk mitigation for airborne pathogens. Obviously, there is a vaccine that’s pretty good at preventing severe disease available for any adult that wants one. For non-pharmaceutical interventions, NIOSH has a hierarchy of controls, illustrated as an inverted pyramid with the most effective measures on top.

PPE is at the bottom. This is because PPE is usually uncomfortable and people often do not wear them correctly or consistently. Keep in mind, “PPE” at minimum are N95 respirators which may have great theoretical efficacy, but evidence is mixed in practice. N95s must be properly fit and leak-tested each time one is worn, otherwise they are essentially useless for airborne pathogens.

Much more effective than PPE, however, is engineering controls — things like ventilation, something as simple as opening windows and doors to allow air to come in and out to help dilute any potential virus particles that are suspended in the air. Despite being higher in the hierarchy, these things are almost never mentioned as instead the narrative has been dominated by masks and distancing.

Just recently, there was a GMA story about a single mom of 4 who chose to not get the COVID vaccine as she was unsure about it, and instead chose to “follow the rules” such as wearing masks and social distancing. Tragically, she passed away of COVID. Is it really hard to imagine many more examples like this across the country, where people opt out of much more effective methods like vaccination because the other prevention methods have been completely oversold over the past 18 months?

The public has been misled into believing they are much safer in an indoor, poorly-ventilated space when the people around them are doing things like wearing masks and social distancing. With COVID-19 becoming endemic, guaranteeing pretty much everyone will be exposed to it, we owe it to people at-risk to tell them the truth and focus on things like vaccination and effective treatment (like monoclonal antibodies). While the science around COVID-19 has changed, we are still using the same prevention methods, as it seems evidence-based policies are no match for bureaucratic inertia. It is immoral and unethical to continue to mislead people at-risk into a false sense of security with these policies. They aren’t effective, and the data have shown this time and time again over the past 18 months.

Academic background in biomedical engineering and computer science. Mainly write about science and technology. Currently work as a software architect.