“Wearing masks in the community probably makes little or no difference.” Such was the verdict of a recent Cochrane review, a systematic assessment of all medical research on masks. How much should one trust this overarching study? Medical journals say that Cochrane reviews are “recognised worldwide as the highest standard in evidence-based healthcare”, are the “best single source of highest-quality systematic reviews”, and are “regarded as the final word in the medical debate on a topic”. One adds, “The main reason is that Cochrane reviews follow a common and specific methodology to limit bias.” If only the same could be said about the public health officials at the Centers for Disease Control (CDC) and the National Institutes of Health (NIH).
Specifically, Cochrane found, “Wearing masks in the community probably makes little or no difference to the outcome of influenza-like illness (ILI)/COVID-19 like illness” — or “to the outcome of laboratory-confirmed influenza/SARS-CoV-2” — “compared to not wearing masks.” Moreover, “The use of a N95/P2 respirators compared to medical/surgical masks probably makes little or no difference for the outcome… of laboratory-confirmed influenza infection.” Each of these claims was made with “moderate certainty”, the second highest of four certainty classifications. (“Moderate certainty” means that “the true effect is likely to be close to the estimate of the effect.”)
The mask advocates’ grasping-at-straws response to this review has been that Cochrane doesn’t know what it’s doing (despite its “worldwide” reputation for providing “the highest standard” of medical research). Or they say that Cochrane produced a fine study, but people didn’t read it correctly. Or randomised controlled trials aren’t to be trusted when it comes to masks (RCTs are universally considered the gold standard in medical research). Or we need more and better RCTs on masks, though 16 have already been conducted on surgical or cloth masks, none of which has provided compelling evidence that they work.
The mask advocates’ refusal to recognise that medical science does not support their steadfast belief is truly remarkable. Clearly, something more is going on here than a genuine debate about which healthcare measures work.
Part of it, perhaps, is that progressives don’t like it when they can’t control something. Masks let them feel as if they can control the virus — and other people, to boot, the next best thing to controlling the virus.
There’s also the matter of identity. For some, a mask conveys quasi-religious symbolism — we believe in Health — and serves as a sort of spiritual symbol, a totem. No one wants to be told that their totem is powerless.
Evidence suggesting masks’ ineffectiveness has remained relatively constant over time. In addition to the individual RCTs conducted across the years, which I discussed in detail in a 2021 City Journal essay reviewing the evidence, Cochrane published a review on November 20th 2020, that closely resembles its January 2023 review. Cochrane’s earlier review found that wearing a mask “probably makes little or no difference to the outcome of laboratory-confirmed influenza… compared to not wearing” a mask, and that using an N95 “compared to” a surgical mask “probably makes little or no difference for the… outcome of laboratory-confirmed influenza infection”. In fact, the 2023 review repeats all of this language verbatim.
Unlike the 2023 Cochrane review, however, the 2020 review didn’t make much of a splash. This may have been by design. Tom Jefferson, the lead author of both studies, says that Cochrane delayed the release of the 2020 study; it “held it up for seven months”. If not for that delay, the review would have appeared just a few weeks after the CDC profoundly reversed its masking guidance — from don’t wear masks to do wear masks — on April 3rd 2020, citing no meaningful new evidence on which to base that change. It’s certainly believable that Cochrane didn’t want to look like it was contradicting the CDC at that pivotal time.
The Australian investigative journalist Maryanne Demasi, who interviewed Jefferson, asked, “Are you suggesting that Cochrane was pro-mask, and that your review contradicted the narrative?” Jefferson replied, “Yes, I think that is what was going on”. He noted that Cochrane wrote a pro-mask editorial to accompany the study’s eventual 2020 release. “Waiting for strong evidence is a recipe for paralysis,” the editorial stated. Such a message, Jefferson observes, is “a complete subversion of the ‘precautionary principle’ which states that you should do nothing unless you have reasonable evidence that benefits outweigh the harms”.
Now the Cochrane executives are at it again. Facing criticism from influential mask advocates, Karla Soares-Weiser, Editor-in-Chief of the Cochrane Library, issued a statement on March 10th — about a month and a half after the 2023 review’s release — saying that “the review is not able to address the question of whether mask-wearing itself reduces people’s risk of contracting or spreading respiratory viruses”. This, of course, is exactly what the review addressed, and it concluded, with “moderate certainty,” that mask-wearing “probably makes little or no difference” in preventing the spread of viruses.
The most noteworthy thing about the 2023 Cochrane review is that it provides further confirmation that the two RCTs that took place after the release of the 2020 Cochrane study — one in Denmark and the other in Bangladesh — didn’t move the needle in favour of masks. In fact, the needle moved in the opposite direction: Cochrane now says that masks “probably” (2023), as opposed to “may” (2020), make “little or no difference to the outcome of influenza-like illness”. (This is in addition to Cochrane’s having previously reported that masks “probably” make “little or no difference to the outcome of laboratory-confirmed influenza”.) And in 2023, Cochrane explicitly added “COVID-19” and “SARS-CoV-2” to the list of things that masks apparently don’t prevent — and could even increase — the spread of.
How could masks increase the spread of viruses? Cochrane suggests the possibilities of “self-contamination of the mask by hands” and “saturation of masks with saliva from extended use (promoting virus survival in proteinaceous material)”. In March 2020, then-Surgeon General Jerome Adams said, “Folks who don’t know how to wear [masks] properly tend to touch their faces a lot and actually can increase the spread of coronavirus.” The authors of one RCT write, “The virus may survive on the surface of the facemasks” and “transfer pathogen from the mask to the bare hands of the wearer”. As for double-masking, the same authors write, “Observations during SARS suggested double-masking… increased the risk of infection because of moisture, liquid diffusion and pathogen retention.” In other words, masks are often moist, frequently dirty and sometimes virus-ridden. Having one stuck to your face could increase the spread of viruses — especially if you touch your mask, or if your young children touch theirs.
The mask zealots, however, remain unmoved. In an article at Health.com responding to the Cochrane review, Sarah Sloat essentially quotes three evidence-denying doctors and rests her case. One declares that masks “are an additional layer of protection” (RCTs be damned). Another asserts, “If you are putting on a mask, you are doing a great job of protecting yourself.” A third opines (with a striking lack of self-awareness), “At the end of the day, people will do what they want, and science is not going to move some people one way or the other.” He then proclaims, “But a mask does give you a big bang for the buck, and not just for COVID-19.”
In Vox, Kelsey Piper complains that the Cochrane review includes studies involving other viruses at other times, rather than just studies focused on Covid during the pandemic. She ignores how the inclusion of the two Covid RCTs resulted in Cochrane’s weighing in more strongly against masks’ effectiveness, as one of those RCTs (the one from Denmark) found no statistically significant difference between infection rates in its mask and non-mask groups, and the other (from Bangladesh) found very little difference and claimed that it was significant only because of myriad methodological flaws, which I detailed in a City Journal essay last summer. Piper, however, praises the highly problematic Bangladesh study as “finding very solid evidence”, while the Cochrane review is somewhat “scientifically irresponsible” and really “quite bad meta-analysis.”
Likewise, Lucky Tran, writing for the Guardian, criticises the Cochrane review because it includes other viruses in addition to Covid and because it evaluates masks’ effectiveness as they are actually worn, rather than trying to guess how effective masks might be if people wore them as diligently as public health officials would like. Tran calls the Cochrane review part of “the avalanche of misinformation” and proclaims, “Masks are magnificent.” He adds that masks “are a visible symbol that the pandemic is ongoing” — another apparent virtue.
Finally, New York Times columnist Zeynep Tufekci writes, without substantiation: “So the evidence is relatively straightforward: Consistently wearing a mask, preferably a high-quality, well-fitting one, provides protection against the coronavirus.” She dismisses the Cochrane review and asserts that the Danish study during Covid “found that masks helped.” This is false. The authors of that study plainly stated that “no statistically significant difference in SARS-CoV-2 incidence was observed” between the study’s mask group and its non-mask control group.
Other mask advocates claim that the problem isn’t with the Cochrane study at all. Instead, they suggest a deeper, esoteric meaning behind what it plainly says: “Wearing masks in the community probably makes little or no difference.” The Los Angeles Times published a column entitled, “Covid deniers claim a new study says mask mandates don’t work. They should try reading it.” A nurse wrote a letter in response asserting, “I have seen with my own eyes how masks protect people from acquisition and transmission of COVID-19.” People generally can’t see viruses with the naked eye, so this is an impressive claim.
Bret Stephens wrote a column in the New York Times entitled, “The Mask Mandates Did Nothing. Will Any Lessons Be Learned?” Times readers’ favourite of the 3,773 comments responding to the article claims that Stephens misrepresents the study, which the reader suggests yielded essentially no information. Their second-favourite comment blames people for not being diligent enough in their mask-wearing and then asks, “Notice how surgeries are still masked environments?” Surgical masks were designed to keep medical personnel from inadvertently infecting patients’ open wounds. Such masks were not designed to reduce the spread of viruses. As for N95s, they were designed to protect workers from breathing in dust, fumes, or smoke. To the extent that they were worn in hospitals pre-Covid, it was primarily to help prevent the spread of tuberculosis bacteria, not to protect against viruses. According to an article on the NIH website, published in the less-politicised, pre-Covid days, “Viruses are tiny, ranging in size from about 20 to 400 nanometers in diameter. … Billions can fit on the head of a pin.” More than 1,000 can generally fit on the period at the end of a sentence, which is roughly “350,000 nanometers, in diameter.” In comparison, “Bacteria are 10 to 100 times larger than viruses” and “are usually measured in microns” (with one micron equaling 1,000 nanometers, the usual measure for viruses).
It should be greatly disturbing, in light of the evidence, that so many hospitals and doctor’s offices continue to force patients to wear masks. It should make one wonder how many other times medical personnel don’t follow the medical studies on which they supposedly rely. Yet, New York Times readers aren’t disturbed at all but take comfort in mask mandates. Among the readers’ 10 favourite comments was one that says, “The [Cochrane] findings are basically nonsense. Common sense prevails here. … I was in a hospital today. Everyone has to wear a mask.”
In his recent City Journal piece on the 2023 Cochrane review, John Tierney asks, “Can anything persuade the maskaholics in the public-health establishment and the public to give up their obsession?” The answer, plainly, is no. Their faith transcends reason.
Jeffrey H. Anderson is president of the American Main Street Initiative, a think tank for everyday Americans. He served as Director of the Bureau of Justice Statistics at the U.S. Department of Justice from 2017 to 2021. This article was first published by City Journal.