Coronavirus FAQ: Is the 6-foot rule debunked? Or does distance still protect you?

We regularly answer frequently asked questions about life in the era of COVID-19. If you have a question you'd like us to consider for a future post, email us at goatsandsoda@npr.org with the subject line: "Coronavirus Questions." See an archive of our FAQs here.

We all remember those early days of the pandemic. I used to run with a mask on outdoors with no one in sight. (Imagine my relief to learn that outdoor air effectively disperses pathogens). I wiped off groceries in case they were contaminated. (Experts now say it’s reasonable to just wash your hands thoroughly after touching stuff.)

And I tried to stay 6 feet away from … well, everyone in public. That’s what the Centers for Disease Control and Prevention recommended back in 2020. Remember those strips of tape plastered to sidewalks leading into banks and in grocery store checkout areas so you wouldn’t accidentally get too close to the next person.

Then in the newly released transcript of a congressional hearing from earlier this year, Dr. Anthony Fauci stated that the 6-foot rule “sort of just appeared” and “wasn’t based on data.”

Those who never liked the idea of physical distancing were thrilled! Ha ha, CDC was wrong!

Now here we are in the summer of 2024. There’s a new, more transmissible variant of COVID-19 circulating and CDC is predicting a summer surge.

This new variant is not considered as likely as past variants to bring on severe disease. But there are people who face a greater risk of serious COVID because of age or infirmities. And no one wants to get sick right before or during a trip.

So the frequently asked question is: Does distancing yourself from others who could be contagious with COVID-19 help in any way? Or has the idea of distance been debunked?

To answer those questions, let’s start by digging into distance.

Did they just pull "6 feet" out of a hat?

The idea behind the CDC recommendation was that putting space between yourself and others was a way to avoid pathogens exhaled by people with COVID.

Was 6 feet just a made-up number? After all, the World Health Organization only suggested 3 feet as a safety zone.

A kinda weird (and relatively ancient) history lesson may offer up a clue.

In the late 1800s, scientists asked people to rinse their mouths with bacteria (editor’s note: yuk) and then just … talk. Crazy!

And what happened? “They saw bacteria landing on plates up to a distance of about 6 feet away,” says Linsey Marr, an aerosols expert and professor of civil and environmental engineering at Virginia Tech.

“But, if they waited longer — several hours -- to collect the plates, allowing time for respiratory particles to drift around the room and settle, they saw bacteria landing on plates much farther than 6 feet away," she adds.

So yeah, 6 feet is not a magic number for avoiding airborne pathogens.

It’s not like if you go one inch further you’re suddenly in a danger zone. It’s more like a speed limit, suggests Dr. Abraar Karan, a infectious disease fellow at Stanford University. “There’s no data to say 55 mph is significantly safer than 56. But you have to have a cutoff that’s reasonable.”

The ABCs of transmission

Now let’s take a detour from distance and think about how COVID spreads. Early in the pandemic, the idea was that the sick person spewed out relatively big, wet droplets that could come into contact with others. These droplets would eventually fall to the ground due to gravity.

But in 2024, “there isn’t much evidence supporting” that route of transmission, says Marr, who did pioneering work to establish that much tinier airborne aerosols can nab you. (She won a MacArthur “genius” grant last year for her research.)

And how far can an aerosol fly? “The distance depends on their size and air currents,” she says. “Their pathway could easily be hundreds of feet before they reach the ground.”

So yes, in theory you could be a lot farther than 6 feet from a sick person and still fall victim to their exhaled pathogens. But ….

Why distance does still matter

Here’s the thing: Even with this revised understanding of the spread of COVID, the closer you are to the person with COVID, the higher your risk of catching it.

“As you get farther away from the infected person, aerosols become more diluted, so the chance of inhaling [particles] usually goes down with distance,” says Marr.

As an analogy, Marr suggests you think about cigarette smoke. Smaller COVID particles “behave like cigarette smoke. If you’re close to someone who exhaled a big puff of smoke, you’re exposed to more than if you’re farther away. The farther away you get, the better.”

Need more convincing? In a study of COVID transmission on a plane from one infected passenger in business class, those who caught the virus were also seated in business class. The study, published in Emerging Infectious Diseases in 2020, reports: “We found a clear association between sitting in close proximity to case 1 and risk for infection.”

Let’s sum up with a quote from Marr: “Distance matters, but there’s nothing magical about 6 feet.”

And an observation from Karan: “People always knew this. You stay away from someone who looks visibly sick.” And while your family members and friends would likely warn you to stay away if they’re feeling sick, you can’t count on that happening in a crowd of strangers.

Layers of safety

So bottom line: Keeping a degree of distance from others can help but should be viewed as one arrow in a quiver of strategies to reduce your risk of catching COVID.

The amount of time you’re exposed to a sick person matters. If you’re going to dash into a store and just breeze past a bunch of customers, some of whom might be infectious with COVID or other diseases, your odds of getting infected are “very low,” says Karan. The less time the better (although again, there’s no magic number).

You might try to keep gatherings outside — outdoor air is your best friend when it comes to dispersing pathogens.

If you’ve had COVID or been vaccinated, that can help you fight off a new infection or at least reduce the severity of disease if you do catch the virus.

A good mask (think N95 or K95) that fits and is worn properly (don’t let your nostrils peek out) is the gold standard. You can’t always control the distance factor, says infectious disease professor Dr. Preeti Malani of the University of Michigan. “But a mask is incredibly effective,” she says. “And what’s the cost of wearing a mask on the plane? Nothing, really!”

Abraar Karan notes that he and colleagues at the hospital where he works do mask up when seeing patients with respiratory diseases — and aren’t catching COVID.

And keep some COVID tests handy – at home or in your trip supplies – just in case you have some symptoms that could be allergies, a cold ... or COVID.

How do you figure out what to do? Our experts say: It depends … on you.

“If you’re concerned about COVID you’re the person who’s going to be responsible,” says Malani. “Others aren’t going to protect you.”

You might amp up your protective measures if…

Your age or medical history puts you at high risk for severe disease.

You’re a caregiver for someone at risk.

You’ll be venturing into an indoor venue with lots of strangers — a gym, a rock concert, a crowded bus, subway car or plane.

You’re planning a trip or family get-together and want to make sure you don’t accidentally infect a more vulnerable family member.

There’s also something you can do for the good of humanity, too. And it involves distance.

“I can’t stress this enough,” says Malani. “If you’re not feeling well don’t put others at risk.” In other words, stay home!