After weeks or even months of lockdown, countries are starting to slowly reopen some parts of society. To avoid a new surge of cases, several distancing and protection measures have been recommended, including the widespread use of face masks out i public — though this is not the case everywhere.

In Austria, people have to wear face masks when shopping. Spain has made face masks compulsory when using public transportation. In Germany face masks or coverings must be worn while in shops, grocery stores, and shopping malls, as well as on local public transportation. In the UK, the government has been lax about recommending face masks, but it is now starting to come around. In many Asian countries, face masks were already common before the coronavirus pandemic, and they’ve only become more widespread in the past couple of months.

Meanwhile, US states have different approaches when it comes to face masks and the federal administration has sent mixed messages. As a result, face masks have become extremely controversial across the country, even though the scientific evidence strongly supports their use.

The science is still not complete, but recent studies are strongly indicating that widespread usage of face masks slows down the virus. If we want to relax the lockdown and not cause a public health disaster, face masks are really paramount.

It’s time to wear masks, researchers say

In an essay published in the British Medical Journal, Professor Trisha Greenhalgh at the University of Oxford and colleagues argue that despite limited evidence, masks “could have a substantial impact on transmission with a relatively small impact on social and economic life.”

When they looked at the literature, Greenhalgh and colleagues found unclear evidence, but here’s the thing: even if masks offer limited protection, this limited protection multiplied with a substantial part of the population wearing masks can make a big difference.

We know that people are infectious before symptoms of COVID-19 start to appear, and many never show any symptoms at all. So the argument is that masks could prevent presymptomatic or asymptomatic carriers from spreading the virus when they are coughing, sneezing, or talking.

Furthermore, masks are cheap and have essentially no risk.

“Masks are simple, cheap, and potentially effective,” they write. “We believe that, worn both in the home (particularly by the person showing symptoms) and also outside the home in situations where meeting others is likely (for example, shopping, public transport), they could have a substantial impact on transmission with a relatively small impact on social and economic life,” they write.

Other researchers share the same message. Babak Javid at Tsinghua University in Beijing and colleagues agree that the public should wear face masks because the benefits are plausible and the harms are very unlikely.

The message was murky in the beginning. Health organizations wanted to protect and prioritize health workers, and feared that if the public would start buying face masks, this would lead to shortages, causing more harm than good. But it’s already been a few months and production has readjusted and shortages have been alleviated for the most part. Also, cloth masks are likely better than wearing no mask at all, Javid and colleagues argue, and a series of recent pre-print articles back this conclusion up.

Multi-layered cotton, in particular, has emerged as a promising alternative to surgical masks, with some studies showing that 4-layer cotton masks can be as effective at filtration as surgical masks.

But even basic masks, made out of an old t-shirt, can offer some protection. A recent study concluded:

“Our findings suggest that a homemade mask should only be considered as a last resort to prevent droplet transmission from infected individuals, but it would be better than no protection.”

While the protection is far from absolute, it is significant, especially when worn by a significant part of society.

Why some people don’t want to wear masks

The objections against face masks are, almost always, not scientific — but rather political and religious. Some people see masks as an infringement on their religious freedom, with Republican legislator Nino Vitale writing:

“This is the greatest nation on earth founded on Judeo-Christian principles. One of those principles is that we are all created in the image and likeness of God. That image is seen the most by our face. I will not wear a mask.”

However, one can’t help but wonder if the image of God also includes a suit and tie, or clothes in general.

Other opponents see face masks as an infringement of freedom, in general, with one extreme case taking place in a supermarket in San Diego: a shopper came in with a face mask covered by a Nazi swastika, allegedly likening the lockdown measures and face mask regulations with Nazi Germany.

This is not exactly an isolated case — there has been a disturbingly high number of similar reports, including Ku Klux Klan masks and threats of violence. For instance, within a day of issuing an emergency proclamation requiring masks, the city of Stillwater, Oklahoma, amended the proclamation after citizens threatened violence.

Psychologists have also identified another trait associated with refusal to wear a mask: toxic masculinity. Basically, many might fear that wearing a mask would make them seem weak and don’t want to wear one out of bravado. If you find this unlikely, just look at authoritarian leaders who want to propagate a “strong man” image.

Donald Trump openly said he doesn’t want to wear a mask, Mike Pence refused to wear a mask even when it was mandatory (although he did admit this a mistake later on), and Brazilian President Jair Bolsonaro outright refuses any precaution against the disease, saying that his health is enough to beat the virus. According to David Abrams, a clinical psychologist and professor of social and behavioral science at New York University’s School of Global Public Health, some men see the mask as a sign of vulnerability.

Wearing masks, even as a temporary measure meant to prevent viral transmission and save lives, seems to be a surprisingly polarizing topic that many outright reject.

We won’t have definitive answers for a while — and we need to take decisions now

There are legitimate, scientific questions about the effectiveness against face masks — essentially, we don’t know just how effective they are, just that they are somewhat effective.

The problem is that testing the efficacy of face masks for a new virus is no easy task. The best way to test their effectiveness is through randomized control trials (where one group has the intervention being tested and another group receives a placebo or no intervention at all). But randomized control trials are essentially impossible to set up in this type of scenario, with such a dangerous disease.

So far, our evidence tends to come from laboratories or influenza studies, both of which are approximations. But here’s the thing: the same thing can be said for washing your hands for 20 seconds or maintaining a distance of 2 meters for social distancing. There aren’t any randomized control trials supporting these issues, but there is still some evidence to support them, so we just do it.

If we turn to empiric correlation, this also seems to support the use of face masks. The city of Jena was the only German city to have imposed mandatory face masks by March 31 and it recorded no new infections in the following eight days while surrounding cities continued to report a surge in cases. The Czech Republic, the first country in Europe to mandate face masks in public, reported slower growth of cases compared to its neighboring countries — very similar places, with very similar strategies, seem to report fewer cases when face masks are introduced into the equation.

So no matter how you go about it, the scientific, medical, and empiric evidence seems to support the widespread use of face masks. They may be unpleasant, they may be a drag — but they can help stop the spread of the disease.

At the very least, there’s nothing to lose.