May 10, 2021 -- The U.S. Centers for Disease Control and Prevention on Friday changed its website guidance on how coronavirus spreads, emphasizing that it's mainly transmitted through the air, not on surfaces.
"COVID-19 spreads when an infected person breathes out droplets and very small particles that contain the virus. These droplets and particles can be breathed in by other people or land on their eyes, noses, or mouth, the agency said. "In some circumstances, they may contaminate surfaces they touch. People who are closer than 6 feet from the infected person are most likely to get infected."
"How people get this virus can be boiled down to three very simple concepts," Dr. John Brooks, chief medical officer for the CDC's COVID-19 response, told CNN. "Keep the air clean, avoid getting exposed on your mucus membranes, and keep your hands clean."
The virus is most commonly caught by standing near someone who is infected and virus particles land on the face or is inhaled. It's less common to catch the virus by breathing contaminated air from people who are further away, or by touching a contaminated surface and then touching the eyes, nose, or mouth, CNN said.
"If you and I are standing within a few feet of each other talking, we now know infectious particles are flying out, even if you are talking softly," Brooks said.
These new insights do not change what people should do, but may help the people to understand how the virus spreads, Brooks said.
People should still wear a mask when near other people or inside, keep a distance from others, wash hands often and get vaccinated.
The CDC added that, "Research supports that mask wearing has no significant adverse health effects for wearers.
"Masks don't just filter the air, Brooks told CNN. "Wearing a mask covers your mucus membranes. It is more difficult to touch your mouth when a mask is over it," he added.
Some scientists say the CDC guidelines are still misleading.The CDC says that "breathing in small droplets and particles [i.e., aerosols] that contain the virus when people are far apart or have been in the same enclosed space for more than a few minutes is uncommon.
This will lead people to continue to think that maintaining distance is sufficient to prevent transmission," six experts said in a letter to the agency. But, it's not, these scientists say.
"We know that transmission at distances beyond six feet occurs because of superspreader events, careful studies of smaller outbreaks, and the physics of aerosols. It can easily happen indoors in a poorly ventilated environment, when people are not wearing masks."
They want CDC to push for better ventilation in places such as meatpacking plants where air is recirculated, and to emphasize the importance of face masks known as respirators, including N95 respirators, in places where people are forced to breathe recycled air, according to CNN.