-A backtrack from the CDC tonight
over how COVID-19 spreads.
-Official guidance posted Friday said airborne transmission
is the primary way the virus is spread.
-The CDC says new changes to its COVID guidance
were posted in error --
guidance that represented a major change
in how coronavirus is transmitted.
-This is not a failure of public health.
It's a failure to support and be guided by public health.
-What was once a win for some health experts
quickly returned to frustration.
For months, many in the scientific community
had been had advocating that aerosols spread COVID-19.
But the CDC maintains that the virus mainly spreads
through large respiratory droplets
encountered at close range.
-We've been frustrated at the health agencies,
and we've frustrated that they've been so slow.
We had enough evidence in March
to say that aerosols were playing a role.
It should have been communicated to the public.
-But why the frustration?
Is the difference between aerosols
and droplet transmission that big?
And what does this mean for the coronavirus pandemic?
To start, aerosols are tiny respiratory particles
that linger in the air.
They linger longer than droplets,
which are larger globs that come from coughing or sneezing.
Aerosols can also transfer at a further distance
than the six-feet average that droplets affect.
We spoke to Jose-Luis Jimenez,
a chemistry professor at the University of Colorado Boulder
who is currently studying aerosol transmission and COVID-19.
-Aerosols and droplets are the same material --
either our saliva or our respiratory fluid,
which is the liquid that wets, you know, our mouths,
our respiratory system.
As we breathe or as we talk, some of those come out of us.
And the difference is their size.
Those droplets are big enough that they could also fly
and hit someone in the eye or the nostrils or the mouth.
And they carry the virus. The infection can start by one.
Aerosols are most of the same material, but they are smaller.
They can float in the air, and it's just like smoke.
Smoke is an aerosol that we can see.
So if the infected person is breathing these aerosols
in a room that has low ventilation,
someone else who's breathing that same air
is sharing the room air and can get infected over time.
-Aerosols indicate airborne transmission.
Some experts believe that airborne transmission
has an implicit negative connotation,
which is why some experts in agencies like the CDC
and the World Health Organization
are hesitant to believe COVID-19 spreads through aerosols.
-We acknowledge that there is emerging evidence in this field.
And therefore we believe that we have to be open to this evidence
and understand its implications.
-People are smart, and they see the contradiction.
And they say, "Well, you are a scientist.
You are telling me the virus is in the air.
But the CDC doesn't say that,
and I trust the CDC more than I trust you as a scientist.
-We need to communicate clearly
that when you put up a document at the CDC
that you have just testified is accurate
and then it's changed to suggest that the risk is more minimal --
by someone for some reason --
it contributes to the massive confusion
that is so troubling to scientists
and so troubling to people.
-While aerosol transmission of COVID-19
means that indoor ventilation will be a key factor
to protecting against the spread,
Dr. Jimenez notes that prevention
means sticking with what most scientists,
like Dr. Anthony Fauci, have been recommending.
-There's always going to be some risk.
Besides, you know, wearing a good mask,
what becomes really important is the fit.
Avoid crowded places,
avoid places with low ventilation,
speak in as low of a voice as possible,
and if you can do it outdoors, you should do it outdoors,
and you should keep your distance.
People think they're safe
in circumstances in which they are not.
That's the most important thing about the guidance.
If the health agencies said that,
then I think we could really make a big dent in the pandemic.
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