The masks help prevent the spread of SARS-CoV-2, the virus that causes COVID-19, although masking policies in the west have presented some dramatic policy errors. Here it is.
1. Ignoring Asia
Soon studies showed that countries (mostly Asian) that made mask wearing mandatory within 30 days of the first case had a dramatically lower number of COVID-19 cases than those (mostly Western) that were delayed beyond 100 days. Instead of taking seriously the theory that masking may have contributed to the low mortality rate, Western countries rejected the fact that wearing a mask as a cultural peculiarity of the so-called collectivist societies or as a popular myth among the less educated.
2. Waiting for perfect tests
While Asian countries soon introduced masks in case they were effective (the precautionary principle), those in the West argued that the best way to act in the face of uncertain evidence was to do nothing. This precaution is suitable for trials of new drugs and vaccines, which can have worse side effects than the disease itself. But a little fabric on your face just doesn’t have the same risks and it’s possible that the delay can cause huge damage.
Instead of asking, “Do we have definitive evidence that masks work?”, We should have asked, “What should we do in a rapidly escalating pandemic, given the empirical uncertainty?”
3. Inflatable speculative damage
Some feared that masks can act as “fomites” (objects that carry disease) because people constantly play with the mask (which can have infected drops on the outside) and then touch their eyes and therefore become infected. However, evidence shows that people actually do touch their face less when wearing masks than when unmasking. But masking was depicted as a highly specialized and potentially dangerous activity that depended on a perfect placement and disposal procedure.
Concern about “risk compensation” (if you wear a mask, you will feel protected and take more risks, like a driver who becomes more reckless when wearing a seat belt) was also without test support.
4. Excessive assessment of randomized controlled trials
In the name of evidence-based medicine, the West became obsessed with the holy grail of a definitive randomized controlled trial (RCT) that would quantify both the benefits and harms of masks, just as it would for a drug. But mask ACEs, in which people are randomly assigned to wear a mask or not and then monitor to see who is infected, are problematic.
First, they can’t measure source control (how much is protected from wearing the mask so you don’t get infected). I agree to wear a mask and also consent to be tested to see if I become infected. But to check if I have transmitted the virus to other people, the whole city must consent to it being tested (at the beginning of the trial and repeatedly) to detect the infection, and this is not feasible.
Second, RCTs performed in short time periods cannot capture exponential changes in transmission. A 10% reduction in the rate of viral transmission can, in repeated cycles of reproduction, lead to a reduction in half of the total number of cases. But a short-term RCT will measure only this initial 10% reduction and consider it “statistically insignificant”.
5. Underestimation of mechanistic evidence
When evaluating a complex phenomenon that develops in a complex system, we need two types of evidence: mechanistic tests to help us understand the causal pathways that relate an intervention (such as wearing a mask) to a specific outcome (such as not capturing COVID-19) and statistical tests to estimate the size of the effect.
Mechanistic tests are often generated in laboratories. For example, measuring the clouds of drops induced by sneezing or using an artificial cough simulator to test the filtration efficiency of different types of masks. These studies do not show that masks work, but they are important pieces of a broader puzzle and should not have been ruled out.
6. Deny airborne spread
There is ample evidence to show that aerial diffusion is the main mode of transmission of SARS-CoV-2, through super-spreading events in poorly ventilated indoor spaces. This is a game changer. It means that we must avoid close contact (aerial propagation occurs mainly less than two meters), prolonged time indoors and congestion.
With masks, we need to change our mechanistic model from a model centered on drop projectile clouds (coughing and sneezing) to one that sees the very air we breathe loaded with infectious particles. For a long time, the World Health Organization denied the airborne nature of this virus. Still, aerial diffusion is done for mask design because it means we have to pay meticulous attention to the fit of the mask (to avoid gaps around the side where air can escape) and you may want to consider upgrading to a higher grade FFP2 mask.
7. Prematurely remove the mandates from the mask
The government of the United Kingdom announcement that masks cease to be mandatory in public places from 19 July is premature. The cases of COVID-19 are rising rapidly and, although vaccination has weakened the link with hospitalization and death, these figures are also increasing. If politicians want to “open up” society despite these continuing risks, continuing to necessarily mask could be a way to do so more safely.