Mask-wearing and distancing at least 3 feet are the best defenses against coronavirus, according to a review of 172 studies

• In the largest review of evidence to date, researchers concluded that physical distancing and mask-wearing are the most effective forms of protection against the novel coronavirus.
• While distancing three feet works, six feet is better. The same goes for certain masks: Surgical masks work, but N95s are better.
• The review is intended to help inform government leaders and health agencies, since advice has been conflicting.

Since the beginning of the coronavirus outbreak, messaging on how people could best protect themselves has been mixed. Wear a mask or save them for healthcare workers? Stay three feet away or six? Wipe down groceries and Amazon deliveries or just doorknobs?

Now, a new review of 172 studies on COVID-19, SARS, and MERS from 16 countries aims to answer some of those questions with the most robust pool of evidence to date.

In it, researchers found that keeping at least a meter (3.28 feet) away from others and wearing a face mask are the best ways to reduce your risk of contracting COVID-19, the disease caused by the coronavirus. They also concluded that wearing eye protection could add even more benefit.

The review found, too, that physical distancing of two meters is better than one, and that N95 masks seem to be superior to surgical masks. Hygiene practices like frequent handwashing are important, though no single method afforded people "complete protection" from the viruses, the study authors said.

While perhaps unsurprising, the findings are important to both encourage future research on protection measures specifically related to COVID-19, and to provide a solid evidence base for government leaders and health officials who dole out recommendations.

"Our findings are the first to synthesize all direct information on COVID-19, SARS, and MERS, and provide the currently best available evidence on the optimum use of these common and simple interventions to help 'flatten the curve,'" study co-author Holger Schünemann from McMaster University in Canada, told Reuters.

Social distancing and mask wearing work because of the way the virus spreads

The coronavirus typically spreads via droplets that jump up to 6 feet when an infected person sneezes, coughs, speaks or sings. If you're nearby and inhale enough of those droplets, you could get sick.

Wearing a mask, then, can help prevent the infected person from spreading those droplets and the people around that person from inhaling them. The farther away you can stay from others, the better.

These measures are especially important if you're inside and not in your home.

"This virus really likes people being indoors in an enclosed space for prolonged periods of close face-to-face contact," William Schaffner, an infectious-disease expert at Vanderbilt University, previously told Insider.