- So I am in week 3 of self quarantining,
- So I am in week 3 of self quarantining,

and now we're in week
and now we're in week

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(dramatic music)

47!
47!

Last spring, we talked with a bunch of experts
Last spring, we talked with a bunch of experts

about what was then a new coronavirus.
about what was then a new coronavirus.

A virus that since then has killed almost 500,000 people
A virus that since then has killed almost 500,000 people

in the U.S. and over 2 million people globally.
in the U.S. and over 2 million people globally.

So today, we're checking back in with some of those experts
So today, we're checking back in with some of those experts

and asking what do we know now that we didn't know then?
and asking what do we know now that we didn't know then?

And how is that information gonna help us
And how is that information gonna help us

in the coming months or years?
in the coming months or years?

(bright music)
(bright music)

(laughing)
(laughing)

Sorry.
Sorry.

(laughing)
(laughing)

Sorry, please continue.
Sorry, please continue.

At the start of the pandemic, we were all wondering
At the start of the pandemic, we were all wondering

when we were gonna get a vaccine so that
when we were gonna get a vaccine so that

life could return to normal.
life could return to normal.

I called up virologist Dr. Ben Neuman,
I called up virologist Dr. Ben Neuman,

who has studied coronaviruses for decades.
who has studied coronaviruses for decades.

And I asked him what do scientists need to know
And I asked him what do scientists need to know

to create a vaccine?
to create a vaccine?

He said it's critical to have an in-depth understanding
He said it's critical to have an in-depth understanding

of the proteins that allow the virus into our cells.
of the proteins that allow the virus into our cells.

Fortunately, we already knew
Fortunately, we already knew

a couple of key things about this coronavirus
a couple of key things about this coronavirus

because a similar one caused the 2003 SARS outbreak.
because a similar one caused the 2003 SARS outbreak.

- [Dr. Neuman] All right, so the SARS coronavirus
- [Dr. Neuman] All right, so the SARS coronavirus

has a protein on the outside called the spike protein.
has a protein on the outside called the spike protein.

And that is going to bump into the ACE2
And that is going to bump into the ACE2

on the outside of a lung cell.
on the outside of a lung cell.

- [Sam] Researchers also knew that SARS-CoV-2
- [Sam] Researchers also knew that SARS-CoV-2

wouldn't be able to infect cells without
wouldn't be able to infect cells without

a co-receptor in addition to ACE2.
a co-receptor in addition to ACE2.

The co-receptor modifies the spike,
The co-receptor modifies the spike,

essentially activating it
essentially activating it

so that once it does bind to ACE2,
so that once it does bind to ACE2,

it can then go on to infect the cell.
it can then go on to infect the cell.

(cash register chimes)
(cash register chimes)

At the time, they suspected that the co-receptor
At the time, they suspected that the co-receptor

was probably a protein called TMPRSS2.
was probably a protein called TMPRSS2.

- [Dr. Neuman] Since then, we have learned about
- [Dr. Neuman] Since then, we have learned about

all the other TMPRSS proteins because, you know,
all the other TMPRSS proteins because, you know,

if there's a two, there're a bunch more,
if there's a two, there're a bunch more,

(laughs)
(laughs)

I think they go up to 11 or 12, and it turns out that
I think they go up to 11 or 12, and it turns out that

at least half of these are able to support infection.
at least half of these are able to support infection.

- [Sam] SARS-CoV-2 can use a bunch of these
- [Sam] SARS-CoV-2 can use a bunch of these

TMPRSS proteins which are all over the place.
TMPRSS proteins which are all over the place.

Brain cells, lung cells, heart cells, cells in your stomach.
Brain cells, lung cells, heart cells, cells in your stomach.

So you would think that all of these cell types
So you would think that all of these cell types

would be able to get infected.
would be able to get infected.

- [Dr. Neuman] People were expecting a lot more
- [Dr. Neuman] People were expecting a lot more

direct infection of the heart,
direct infection of the heart,

a lot more direct infection of the brain.
a lot more direct infection of the brain.

Evidence for both of those is still not particularly strong.
Evidence for both of those is still not particularly strong.

- [Sam] There have been some reports of patients
- [Sam] There have been some reports of patients

with heart inflammation or symptoms in other parts
with heart inflammation or symptoms in other parts

of the body, but actual direct infection
of the body, but actual direct infection

by the virus seems pretty rare.
by the virus seems pretty rare.

After a year, it's clear that it's mainly infecting
After a year, it's clear that it's mainly infecting

our lungs, but it's not clear as to why.
our lungs, but it's not clear as to why.

So why does figuring that out matter?
So why does figuring that out matter?

Why should we care about this?
Why should we care about this?

We already have a couple of vaccines against SARS-CoV-2.
We already have a couple of vaccines against SARS-CoV-2.

Well, you've seen the news.
Well, you've seen the news.

There are other variants of SARS-CoV-2 that are emerging,
There are other variants of SARS-CoV-2 that are emerging,

and if this virus mutates to the point
and if this virus mutates to the point

where current vaccines are no longer effective,
where current vaccines are no longer effective,

we're going to need to re-engineer them.
we're going to need to re-engineer them.

And if we wanna do that, it's critical that we have
And if we wanna do that, it's critical that we have

as in depth an understanding of this virus as possible.
as in depth an understanding of this virus as possible.

In the meantime, some of these emerging variants
In the meantime, some of these emerging variants

could be more transmissible. Which means wearing a mask
could be more transmissible. Which means wearing a mask

is more important than ever.
is more important than ever.

Early info on masks, at least in the U.S. was confusing.
Early info on masks, at least in the U.S. was confusing.

So back in April, we talked with an expert
So back in April, we talked with an expert

to try to get a straight answer.
to try to get a straight answer.

- N-95 better than surgical mask, better than cloth mask.
- N-95 better than surgical mask, better than cloth mask.

But when you set that against what your actual risk
But when you set that against what your actual risk

and needs are by population,
and needs are by population,

a cloth mask is perfectly fine for the general public.
a cloth mask is perfectly fine for the general public.

- [Sam] And it turns out, well?
- [Sam] And it turns out, well?

- [Dr. Soe-Lin] I've always said that the three, my three
- [Dr. Soe-Lin] I've always said that the three, my three

favorite words in the English language,
favorite words in the English language,

are not like, 'I love you', it's 'you were right'.
are not like, 'I love you', it's 'you were right'.

(laughing)
(laughing)

- [Sam] There are now dozens of studies showing that
- [Sam] There are now dozens of studies showing that

cloth masks work, but that's not to say that
cloth masks work, but that's not to say that

all cloth masks are created equal.
all cloth masks are created equal.

Here's what we've learned so far:
Here's what we've learned so far:

multilayer high thread count cloth masks
multilayer high thread count cloth masks

block upwards of 80% of all respiratory droplets
block upwards of 80% of all respiratory droplets

coming from the person wearing the mask,
coming from the person wearing the mask,

and more than half
and more than half

of the really small droplets and particles.
of the really small droplets and particles.

Even those tiny particles that do get through,
Even those tiny particles that do get through,

don't travel as far.
don't travel as far.

The effectiveness of some cloth masks
The effectiveness of some cloth masks

even seems to be on par with surgical masks.
even seems to be on par with surgical masks.

And we've learned that masks
And we've learned that masks

don't just protect other people,
don't just protect other people,

they protect the person wearing the mask too.
they protect the person wearing the mask too.

It may seem obvious now,
It may seem obvious now,

but early in the pandemic, we didn't know that.
but early in the pandemic, we didn't know that.

- [Dr. Soe-Lin] I didn't think
- [Dr. Soe-Lin] I didn't think

it was gonna be this effective.
it was gonna be this effective.

I just, at the beginning was feeling somewhat desperate
I just, at the beginning was feeling somewhat desperate

that we didn't have anything.
that we didn't have anything.

So I thought, you know, all of the primary literature had
So I thought, you know, all of the primary literature had

shown that maybe it was going to be a 20% effect.
shown that maybe it was going to be a 20% effect.

I thought, well, 20% is better than nothing.
I thought, well, 20% is better than nothing.

You should take that.
You should take that.

I didn't think it was going to be this sweeping.
I didn't think it was going to be this sweeping.

- With these new variants of SARS-CoV-2,
- With these new variants of SARS-CoV-2,

that could be more transmissible,
that could be more transmissible,

some European countries are requiring
some European countries are requiring

that people wear medical grade masks when in public.
that people wear medical grade masks when in public.

This is a quickly changing situation.
This is a quickly changing situation.

So keep an eye on CDC guidelines.
So keep an eye on CDC guidelines.

We left a link in the video description.
We left a link in the video description.

Either way, it's clear that masks work
Either way, it's clear that masks work

Social distancing works.
Social distancing works.

But there was another recommendation
But there was another recommendation

that we were getting early on.
that we were getting early on.

- [Dr. Soe-Lin] Remember they were still saying,
- [Dr. Soe-Lin] Remember they were still saying,

"wash your hands"?
"wash your hands"?

- [Sam] Yeah.
- [Sam] Yeah.

- [Dr. Soe-Lin] I mean like wash your hands is important,
- [Dr. Soe-Lin] I mean like wash your hands is important,

you should wash your hands anyway
you should wash your hands anyway

but I wish we could wash our hands out of this epidemic.
but I wish we could wash our hands out of this epidemic.

I mean, it wasn't even fully appreciated
I mean, it wasn't even fully appreciated

how aerosolized this virus was.
how aerosolized this virus was.

- [Sam] Soap was the thing at the start of the pandemic.
- [Sam] Soap was the thing at the start of the pandemic.

Our first COVIDeo,
Our first COVIDeo,

Get it? COVID E O.
Get it? COVID E O.

Our first COVIDeo was about the chemistry
Our first COVIDeo was about the chemistry

behind how soap kills SARS-CoV-2.
behind how soap kills SARS-CoV-2.

- These surfactants can actually wedge their way
- These surfactants can actually wedge their way

into the lipid bilayer, lipophilic end first,
into the lipid bilayer, lipophilic end first,

and when they do, the virus will break apart.
and when they do, the virus will break apart.

(cracking sound)
(cracking sound)

- [Sam] Soap does kill the virus. That hasn't changed.
- [Sam] Soap does kill the virus. That hasn't changed.

It's just that at the time, we didn't realize
It's just that at the time, we didn't realize

that we were almost exclusively spreading this virus
that we were almost exclusively spreading this virus

through the air.
through the air.

- [Sam] Dr. Soe-Lin was right.
- [Sam] Dr. Soe-Lin was right.

Masks are a great way to help prevent infection.
Masks are a great way to help prevent infection.

But what do we do for someone who does get infected?
But what do we do for someone who does get infected?

Last May, we looked into drugs
Last May, we looked into drugs

that have the potential to block SARS-CoV-2 infection,
that have the potential to block SARS-CoV-2 infection,

or stop it before it gets really bad.
or stop it before it gets really bad.

Those drugs are called antivirals.
Those drugs are called antivirals.

- Whenever you take a drug so far as to be in people,
- Whenever you take a drug so far as to be in people,

there's always a hope that you can revive it
there's always a hope that you can revive it

for something else.
for something else.

And sometimes drugs can affect more than one virus
And sometimes drugs can affect more than one virus

even if you developed it for Ebola.
even if you developed it for Ebola.

So people said, let's test it.
So people said, let's test it.

- He's talking about a drug
- He's talking about a drug

that you might actually have heard of.
that you might actually have heard of.

It's called Remdesivir.
It's called Remdesivir.

- [Sam] In the fall of last year,
- [Sam] In the fall of last year,

the NIH concluded that Remdesivir works,
the NIH concluded that Remdesivir works,

kinda.
kinda.

It seems to shorten recovery time and it may help
It seems to shorten recovery time and it may help

prevent progression to more severe versions of COVID-19.
prevent progression to more severe versions of COVID-19.

But here's the problem.
But here's the problem.

- [Vincent Racaniello] It's main effect is to
- [Vincent Racaniello] It's main effect is to

block virus reproduction.
block virus reproduction.

And that is not your problem once you're in the hospital.
And that is not your problem once you're in the hospital.

Your problem is you have an over exuberant immune response
Your problem is you have an over exuberant immune response

that is causing all these problems
that is causing all these problems

in your lungs and other organs as well.
in your lungs and other organs as well.

That's one of the things we have learned that, you know,
That's one of the things we have learned that, you know,

this disease, you initially have a viral infection
this disease, you initially have a viral infection

of your upper tract, which lasts maybe 10 days,
of your upper tract, which lasts maybe 10 days,

but then you have this immune response
but then you have this immune response

that causes incredible disease.
that causes incredible disease.

And so they were giving Remdesivir
And so they were giving Remdesivir

to people who were hospitalized.
to people who were hospitalized.

And by then, an antiviral is not what you need.
And by then, an antiviral is not what you need.

It's too late.
It's too late.

At that point, you don't need an anti-viral,
At that point, you don't need an anti-viral,

you need to dampen down your immune response.
you need to dampen down your immune response.

- [Sam] Once you're at the point where you need
- [Sam] Once you're at the point where you need

to go to the hospital, SARS-CoV-2 has had
to go to the hospital, SARS-CoV-2 has had

a lot of time to replicate and spread.
a lot of time to replicate and spread.

And most of it's been cleared up by your immune system,
And most of it's been cleared up by your immune system,

which is now in overdrive.
which is now in overdrive.

You don't die from SARS-CoV-2,
You don't die from SARS-CoV-2,

you die from your immune system's response to it.
you die from your immune system's response to it.

So yes, Remdesivir can help stop the virus from replicating,
So yes, Remdesivir can help stop the virus from replicating,

but in severe cases of COVID,
but in severe cases of COVID,

the virus is really not the problem anymore.
the virus is really not the problem anymore.

- [Dr. Neuman] Say the virus is like a stick of dynamite
- [Dr. Neuman] Say the virus is like a stick of dynamite

and say the disease is like the avalanche.
and say the disease is like the avalanche.

The stick of dynamite starts it.
The stick of dynamite starts it.

But you know, what the antivirals do
But you know, what the antivirals do

is they try to put out the little fuse on the dynamite.
is they try to put out the little fuse on the dynamite.

Once that has blown, the avalanche is coming,
Once that has blown, the avalanche is coming,

whether you like it or not.
whether you like it or not.

And you know, you can pour all the water you want
And you know, you can pour all the water you want

on the remains of the dynamite
on the remains of the dynamite

but it is not going to stop the avalanche, yeah.
but it is not going to stop the avalanche, yeah.

And so we don't really have anything that can slow
And so we don't really have anything that can slow

- ...down the immune response. - [Sam] That is such a great metaphor.
- ...down the immune response. - [Sam] That is such a great metaphor.

Andrew, did you catch that?
Andrew, did you catch that?

(laughing)
(laughing)

- Sorry.
- Sorry.