A new study on how influenza is transmitted from person to person may shed more light on how the coronavirus spreads.

Dr. Don Milton, an environmental health researcher and aerosol transmission expert at the University of Maryland, found that when people infected with the flu virus mingled with healthy people in a poorly ventilated room, the infection rate was 8%. However, when the same experiment was repeated in a room with better air flow, the rate of infection fell to 1.3%.

According to The New York Times, while the flu virus is not the same as the coronavirus, Milton’s experiments show that pathogens can be transmitted in the air, and not just by close contact with symptomatic people or the surfaces they touched.

Last week the World Health Organization acknowledged that the coronavirus may linger in the air in crowded spaces after stating that this type of transmission is unlikely. However, growing scientific and anecdotal evidence prompted the organization to change its stance.

Dr. Linsey Marr, an expert in the spread of aerosols at Virginia Tech, says that Milton’s results show how important good ventilation is to reduce the risk of viral transmission. A study published in March in the New England Journal of Medicine stated that aerosolized coronavirus particles can live up to three hours in the air, meaning that they could infect people hours after being expelled.

Recently, a study from Tulane University found that the longevity of the pathogen was far greater than expected. Marr said she’s been studying the mechanism of transmission of aerosols for a decade and acknowledges that scientists still have a long way to go before they fully understand how they spread, she told the Times. However, the new research shows the importance of airborne transmission.

“In the last four months, I’ve seen a greater willingness to consider the importance of aerosols than I’ve seen in the past 12 years,” she said.