Get Healthy!

• Posted January 13, 2026

They Spent Hours In A Room Full Of Flu Patients And Walked Out Healthy — Here's How

Stick some flu patients in a confined hotel room with a group of healthy volunteers for hours on end, whiling away the time with conversation or card games.

What do you figure will happen?

Nothing, it turns out.

Not a single person caught the flu from a room full of college-aged flu patients in this bold real-world experiment, researchers reported Jan. 7 in the journal PLOS Pathology.

This had nothing to do with vaccination. In fact, only a couple of the healthy participants had gotten a flu jab, researchers said.

Instead, it appears that limited coughing among the flu patients and good circulation of the indoor air protected the healthy people from their sick comrades.

Although the infected folks had high levels of virus in their noses, the fact they rarely coughed meant only small amounts of virus were released into the air, said lead investigator Jianyu Lai, a post-doctoral research scientist at the University of Maryland.

“Our data suggests key things that increase the likelihood of flu transmission — coughing is a major one," Lai said.

This data could come in handy, as this year’s flu season has been especially harsh, researchers noted.

At least 15 million Americans have fallen ill with the flu this season, including 7,400 deaths, the U.S. Centers for Disease Control and Prevention (CDC) estimates. 

A new variant called subclade K has proven incredibly virulent, driving the spread of flu across the U.S.

The striking experiment took place on a quarantined floor of a Baltimore-area hotel. It occurred in two waves, in 2024, involving two separate groups of people who stayed in the hotel for two weeks.

In one wave, one flu patient spent time with eight healthy people during six specific events where they were required to socialize in close quarters.

In the other, four flu patients hung out with three healthy people 17 times, in what the researchers called “exposure events.”

These exposure events lasted between 111 and 250 minutes, totaling dozens of hours in all — nearly 20 for the first group and nearly 63 for the second.

The events included conversation with ice-breaker questions, games involving cards and tablets, and even some physical activity with yoga or dancing, researchers said.

Infected people and healthy folks handled the same markers, tablet computers and microphones, which were passed around the group.

Researchers closely tracked everyone’s symptoms and collected daily nasal swabs, saliva samples and blood draws to monitor infection. They also measured the indoor air for virus, as well as people’s exhaled breath.

In the end, none of the healthy people got sick.

"At this time of year, it seems like everyone is catching the flu virus. And yet our study showed no transmission — what does this say about how flu spreads and how to stop outbreaks?" senior researcher Dr. Donald Milton, a professor of global, environmental and occupational health at the University of Maryland, said in a news release.

A lack of coughing appeared to keep the air free from virus, researchers said.

Ventilation also appears to have played a key role.

“The air in our study room was continually mixed rapidly by a heater and dehumidifier and so the small amounts of virus in the air were diluted," Lai said.

In addition, it might have mattered that the healthy people were all middle-aged. Middle-aged adults tend to be less vulnerable to flu than young adults, Lai said.

All told, the experiment provides some valuable clues that could help people stay healthy, Milton said.

"Being up close, face-to-face with other people indoors where the air isn't moving much seems to be the most risky thing — and it's something we all tend to do a lot,” he said.

“Our results suggest that portable air purifiers that stir up the air as well as clean it could be a big help,” Milton said. “But if you are really close and someone is coughing, the best way to stay safe is to wear a mask, especially the N95.”

More information

The U.S. Centers for Disease Control and Prevention offers healthy habits that can prevent flu.

SOURCES: University of Maryland, news release, Jan. 11, 2026; PLOS Pathology, Jan. 7, 2026