The Centers for Disease Control and Prevention (CDC) now admits that coronavirus does spread through airborne transmission, according to updated guidance on the agency's website.
It comes two weeks after CDC officials said their previous warning about airborne transmission was 'in error,' making Monday's update the third time in a month the agency has flip-flopped on how the virus spreads.
'There is evidence that under certain conditions, people with COVID-19 seem to have infected others who were more than six feet away,' the latest guidance reads.
'In these instances, transmission occurred in poorly ventilated and enclosed spaces that often involved activities that caused heavier breathing, like singing or exercise. Such environments and activities may contribute to the buildup of virus-carrying particles.'
If the virus does spread in fine particles, six feet of distance from an infected person would not necessarily be enough to protect you from catching the virus - but whether or not this is a significant mode of transmission is still hotly debated.
The CDC has made a series of gaffs and been forced to backtrack statements in recent months, and the number of Americans who say they place faith in officials there has fallen 16 percent since April, according to a recent Kaiser Health Family Foundation survey.
On Monday, the CDC updated its guidance to warn that coronavirus can spread through the air, despite retracting similar guidance that it said was posted 'in error' two weeks ago. Pictured: CDC director Dr Robert Redfield pauses while speaking at a Senate Appropriations subcommittee hearing last month
The CDC now recognizes that 'some infections' can spread through the in tiny particles and 'can linger in the air for minutes to hours.'
Measles, tuberculosis and chickenpox commonly spread this way, according to the CDC.
Diseases that spread through the air in fine particles of saliva and mucus, known as aerosols, are especially dangerous because an infected person does not have to be coughing or sneezing to expel contagious particles.
They can be released just by talking or breathing, and because they are so small they can drift further from their source before falling to the ground.
For coronavirus, the CDC suspects that the amount of these small particles can become concentrated enough to cause an infection, but most likely only in enclosed spaces.
CDC's previous, mistakenly posted guidance said coronavirus can spread through 'respiratory droplets or small particles, such as those in aerosols, produced when an infected person coughs, sneezes, sings, talks, or breathes.'
These particles can be inhaled and 'this is thought to be the main way the virus spreads' it continued.
Effectively, this described aerosols and larger droplets as playing similar roles in the spread of coronavirus.
Research thus far does not support the theory that they play comparable roles.
The World Health Organization (WHO) said it contacted the CDC on September 21, to ask about the sudden update to its transmission guidance.
During a news conference, Dr Mike Ryan, executive director of the WHO's health emergencies program, said the WHO had not seen 'new evidence' regarding airborne transmission and that it reached out to CDC to 'better understand' why the