The US Centers for Disease Control and Prevention updated guidance on its site to state coronavirus can generally spread"via respiratory droplets or tiny particles, like those from aerosols," that are generated even when a individual breathes.
"Airborne viruses, including COVID-19, are one of the very contagious and easily spread," the site now says.
Previously, the CDC page said that Covid-19 was considered to spread mainly involving people in close contact -- roughly 6 feet -- and"through respiratory droplets produced when an infected person coughs, sneezes or talks."
The webpage, updated Friday, nevertheless states Covid-19 most commonly spreads between people who are in close contact with one another, and now says the virus is known to disperse "via respiratory droplets or tiny particles, like those in aerosols, produced when an infected person coughs, sneezes, sings, discussions or breathes."
These particles may cause disease when "inhaled into the nose, mouth, airways, and lungs," it says. "This is thought to be the main way the virus spreads."
"There is increasing evidence that droplets and airborne particles may remain suspended in the air and be breathed in by others, and travel distances beyond 6 ft (for example, through choir practice, in restaurants, or in gym courses )," the webpage now says. "In general, indoor environments without great ventilation raise this danger."
The CDC also added new measures to its information about protecting yourself and others.
Previously, CDC suggested maintaining "great social distance" of about 6 feet, washing hands, routinely cleaning and disinfecting surfaces and covering your nose and mouth with a mask when around others.
Now, it says"stay at least 6 feet away from others, whenever possible," and proceeds to direct people to wear a mask and regularly clean and disinfect. However, it also now says people should stay home and isolate when ill, and"utilize air purifiers to reduce airborne germs in indoor spaces."
Masks, it notes, shouldn't replace other prevention measures.
The update also shifted language about asymptomatic transmission, changing from stating"some people without symptoms may have the ability to spread the virus" to saying"people that are infected but don't show symptoms may spread the virus to other people."
Scientists pushed for acknowledgment of airborne transmission
For many years, scientists have noted the probability of coronavirus transmission through viral particles from the atmosphere, also pushed health bureaus to admit it.
Back in April, a prestigious scientific panel advised the White House in a letter that study showed coronavirus can be spread not only by sneezes or coughs, but also by simply talking, or possibly even only breathing.
"While the current [coronavirus] specific study is limited, the results of available studies are consistent with aerosolization of virus from normal breathing," according to the letter, written by Dr. Harvey Fineberg, former dean of the Harvard School of Public Health and chair of the NAS' Standing Committee on Emerging Infectious Diseases and 21st Century Health Threats.
"Currently available research supports the chance that [coronavirus] could be spread via bioaerosols made directly by patients' exhalation," the letter said.
And in July, 239 scientists published a letter that encouraged the World Health Organization and other public health associations to be more forthcoming regarding the likelihood that individuals can catch the virus from droplets that were floating in the air.
"Most public health organizations, such as the World Health Organization, do not recognize airborne transmission except for aerosol-generating processes performed in health care settings. Hand washing and social distancing are appropriate, however in our view, inadequate to provide protection against virus-carrying respiratory microdroplets introduced into the air by infected people," they added.
Following the correspondence printed, WHO published a report that detailed how the coronavirus can pass from one individual to another, such as through the atmosphere during certain medical procedures and the air in humid indoor spaces.
"I'm very encouraged to find that the CDC is paying attention and moving with the science. The evidence is amassing," Milton wrote in an email to CNN.
He explained a pre-print newspaper released in August -- in which scientists described culturing viable virus from air in a hospital -- as"an important addition to the reports of large outbreaks which were clearly a result of transmission by aerosols that traveling over 6 feet."
"Airborne viruses, including COVID-19, are one of the very contagious and easily spread," the site now says.
Previously, the CDC page said that Covid-19 was considered to spread mainly involving people in close contact -- roughly 6 feet -- and"through respiratory droplets produced when an infected person coughs, sneezes or talks."
The webpage, updated Friday, nevertheless states Covid-19 most commonly spreads between people who are in close contact with one another, and now says the virus is known to disperse "via respiratory droplets or tiny particles, like those in aerosols, produced when an infected person coughs, sneezes, sings, discussions or breathes."
These particles may cause disease when "inhaled into the nose, mouth, airways, and lungs," it says. "This is thought to be the main way the virus spreads."
"There is increasing evidence that droplets and airborne particles may remain suspended in the air and be breathed in by others, and travel distances beyond 6 ft (for example, through choir practice, in restaurants, or in gym courses )," the webpage now says. "In general, indoor environments without great ventilation raise this danger."
The CDC also added new measures to its information about protecting yourself and others.
Previously, CDC suggested maintaining "great social distance" of about 6 feet, washing hands, routinely cleaning and disinfecting surfaces and covering your nose and mouth with a mask when around others.
Now, it says"stay at least 6 feet away from others, whenever possible," and proceeds to direct people to wear a mask and regularly clean and disinfect. However, it also now says people should stay home and isolate when ill, and"utilize air purifiers to reduce airborne germs in indoor spaces."
Masks, it notes, shouldn't replace other prevention measures.
The update also shifted language about asymptomatic transmission, changing from stating"some people without symptoms may have the ability to spread the virus" to saying"people that are infected but don't show symptoms may spread the virus to other people."
Scientists pushed for acknowledgment of airborne transmission
For many years, scientists have noted the probability of coronavirus transmission through viral particles from the atmosphere, also pushed health bureaus to admit it.
Back in April, a prestigious scientific panel advised the White House in a letter that study showed coronavirus can be spread not only by sneezes or coughs, but also by simply talking, or possibly even only breathing.
"While the current [coronavirus] specific study is limited, the results of available studies are consistent with aerosolization of virus from normal breathing," according to the letter, written by Dr. Harvey Fineberg, former dean of the Harvard School of Public Health and chair of the NAS' Standing Committee on Emerging Infectious Diseases and 21st Century Health Threats.
"Currently available research supports the chance that [coronavirus] could be spread via bioaerosols made directly by patients' exhalation," the letter said.
And in July, 239 scientists published a letter that encouraged the World Health Organization and other public health associations to be more forthcoming regarding the likelihood that individuals can catch the virus from droplets that were floating in the air.
"Most public health organizations, such as the World Health Organization, do not recognize airborne transmission except for aerosol-generating processes performed in health care settings. Hand washing and social distancing are appropriate, however in our view, inadequate to provide protection against virus-carrying respiratory microdroplets introduced into the air by infected people," they added.
Following the correspondence printed, WHO published a report that detailed how the coronavirus can pass from one individual to another, such as through the atmosphere during certain medical procedures and the air in humid indoor spaces.
"I'm very encouraged to find that the CDC is paying attention and moving with the science. The evidence is amassing," Milton wrote in an email to CNN.
He explained a pre-print newspaper released in August -- in which scientists described culturing viable virus from air in a hospital -- as"an important addition to the reports of large outbreaks which were clearly a result of transmission by aerosols that traveling over 6 feet."