SARS-CoV-2 and You Transcript
Hey there. My name's Will Henriques, and I'm a graduate student in the Department
of Microbiology and Immunology at Montana State University.
So this is a picture of me in my lab. I'm going to get the pointer going here.
So, like I said, this is a picture of me in my lab and microbiology and immunology,
this department that I'm in.
Those are just two fancy words for what I like to call tiny biology.
And today I want to talk to you about some tiny biology that has been impacting
all of us in the last year.
And that's SARS-CoV-2. Now, SARS-CoV-2 might not be familiar to you as a term,
but I'm sure you've heard of COVID-19 .
COVID-19 is an acronym, and it stands for Coronavirus Disease .
And we talked onto the end of that name because the corona virus that causes
the disease was discovered in .
And that Corona virus is known as SARS-CoV-2.
So SARS stands for Severe Acute Respiratory Syndrome, SARS and COVI stands for
coronavirus.
And then two, because this is the second epidemic or pandemic causing coronavirus
that we've seen.
So SARS-CoV-2. Now, I think it's important to put a face to the name.
So here's a picture that I took of three SARS-CoV-2 viral particles.
We got one, two and three, and they're about nanometers across this way now.
And in a meter isn't something that you think about much going to the grocery
store or eating breakfast.
It's a billionth of a meter now, a billionth of a meter.
That's sort of a mind boggling number to try and wrap your head around. So I want
you to think about it like this.
Think about the United States, which is kilometers across. Now.
Look down at your shoe. Your shoe is about a billionth of the size of the length
of the United States.
So these are really tiny particles, and we need this fancy microscope, which is
kind of like driving a spaceship using one of these.
They're called transmission electron microscopes. They're fun. So we use these
to look at viral particles.
And fortunately, there are better microscopist and better photographers out there
than me.
And these this is a picture of three SARS-CoV-2 particles is actually taken at
the Rocky Mountain Laboratories in Hamilton, Montana.
So shout out to Montana there and the coronavirus particles here, you can really
see clearly colored in dark green.
The corona of these particles, corona just means Latin in crown.
So coronaviruses get this name from this corona around the outside of the viral
particle.
Now, as I mentioned previously, we've seen coronaviruses capable of causing epidemics.
Before the first SARS coronavirus.
SARS-CoV-2 was first seen in China in , and it was more deadly and less contagious.
So it died out relatively quickly.
The second time we saw it was actually another Corona virus, but this was called
the Middle Eastern Respiratory Syndrome or merged coronavirus.
And it appeared in Saudi Arabia in , actually first in camels.
And we know that there are more distantly related coronaviruses that are capable
of causing the common cold.
We've known about those for a few decades now. Now, most coronaviruses, it seems
that their natural hosts are actually in bats.
So bats are an incredibly diverse group of mammals.
And sometimes what happens is that a virus from a bat will become capable of infecting
a human, which is the case in SA with SARS-CoV-2.
And so one of the things that I want to drive home,
if you walk away from this presentation with anything, it's this a virus needs
a host to replicate.
Viruses can't make copies of themselves on their own like cells can.
The viruses need to invade cells and turn those cells into viral factories.
Now, remember that a cell is the building block of all biology.
You, as a human are made up of about trillion cells.
And in the case of SARS-CoV-2, it likes to make viral factories out of the cells
of our upper respiratory tract, so the cells of our lungs,
our throat and our nose, and primarily it enters into your upper respiratory tract
riding on respiratory droplets.
So small little liquid droplets that are in the air whenever you breathe or talk,
or aerosols which are even smaller droplets than respiratory droplets that are
generated by coughing or sneezing.
And then you can also get SARS-CoV-2 through close contact with contaminated surfaces.
So what happens is SARS-CoV-2 gets into your upper respiratory tract and it turns
those cells into viral factories.
So here we have a cell in red, the sort of brain looking blob.
And it's this is actually a single cell from a patient who is infected with SARS-CoV-2.
And this cell has been successfully turned into a viral factory.
And you can see all of these gold particles. These are SARS-CoV-2 viral particles
leaving the cell.
And there's really one step to becoming a viral factory if you're a cell, and
that's exposure.
And there's also one step to becoming a viral factory if you're a person, and
that's exposure.
So what does exposure mean? Well, let's just say we're going to use these three
viral particles to as as a representation of infection.
So this purple person is infected with SARS-CoV-2.
And because they're infected and contagious SARS-CoV-2, viral particles are also
in the respiratory droplets that they're exhaling.
And so this blue person is closer than six feet and they're not wearing a mask.
They're chatting over coffee. And so they're breathing in those respiratory droplets
that contain the viral particles.
And we say that this blue person is exposed. And so we're going to start the count
the of the course of their infection on day zero here,
the day that they were breathing in those viral particles. Now,
SARS-CoV-2 is a tricky virus because it has this incubation period where whoever's
infected does not feel sick and that incubation period can last to days.
So it typically lasts five. And during that period, you're asymptomatic.
So that just means you're not feeling sick.
But at some point, usually between days five and , the cells in your body have
become viral factories to the point where you're now contagious.
I want to remind you, with this picture of this cell, there's a viral factory
down here with the technical term.
This show is this cell is now shedding virus.
And that means that the cell or someone who's infected with coronavirus and who
has cells that look like this is able to spread the virus,
they're contagious. And in the case of SARS-CoV-2, this typically happens one,
two to to days excuse me, before symptom onset.
Now, symptom just means sick. So when you start to feel symptoms, you're starting
to feel sick.
And for about , so out of people will feel a mild form of the disease.
They'll develop a fever, they'll feel tired and maybe a dry cough.
And some people are actually reporting that they're losing their sense of smell
or taste, which is strange.
And any time between this point where you're you're feeling sick and in this pre-symptomatic
period,
you're capable of spreading the virus to other people.
Now, for two out of ten or out of people, the disease will progress to a more
serious form.
And this will involve hospitalization and perhaps even death.
And there are certain risk factors that increases the chances that someone will
become more seriously ill.
And those risk factors are age, diabetes, smoking, pregnancy, heart disease and
obesity.
Now, in Montana, we have been lucky.
We only seeing four out of people or % have been hospitalized.
Of the people who have been infected with SARS-CoV-2 and only about % or one in
a hundred have died from the disease.
However, nationally, the pandemic looks pretty bad.
And if I were to give it a grade, I'd give the United States an F for handling
the pandemic hands down.
And there are three graphs that inform my decision to grade the United States
with an F.
The first is in this top left corner where we have the number of cases per , people
in the population.
And this is the total number of cases, which means the number of current infections,
the number of people who have been infected but have now recovered. That's what
this black and white photo represents.
And then the number of people who have died, who have been infected and died.
And you can see that the total number of infections per , in the United States,
when the pandemic started in March, we were on par with the rest of the world.
There weren't very many infections, but you can see our rate of infection slowly
and then more rapidly this fall going up.
And you can see that we are far above the rest of the world.
Brazil was close for a little while, but now we have more infections per , people
than any other country.
Another way of looking at that is the number of new cases reported each day.
So these are the people every day who have tested positive for coronavirus.
And in the United States, you can see that again. When the pandemic started in
March, there weren't so many new cases each day.
And then late March, early April, we see a lot of new cases in the United States
every day.
And then that tapers off. And India and Brazil catch up to us for a little bit.
But you can see now late this fall, we have more new cases every day than any
other country where head and shoulders above the rest.
And we're seeing about , new cases a day. Now, three weeks ago, we were seeing
about , , new cases a day.
And I want to remind you that the death rate is about two and .
So %. It's actually .%.
But we'll round up for the sake of argument. So right now, we're seeing between
people dying every day.
So that's about % of the people who were infected three weeks ago.
That number is likely going to go up because look at the number of infections
we have.
Now, this is the status from December th. And you can see the death rate in the
United States.
This is the third graph that's going to give the United States their f r death
rate has been slowly climbing over the course of the pandemic,
the number of deaths per , people in the population. We are leading the world
along with Brazil, Italy and the U.K.
Now, I want to speak for just a couple of seconds here on this topic called herd
immunity.
So herd immunity, you might you might have heard that term thrown around.
What it means is that the virus has run out of hosts to replicate it.
Now, herd immunity has never been achieved naturally in a population. It's only
ever been achieved by vaccination.
And so what it means is that there are enough people that are immune to the virus
because they've been infected or because they've received a vaccine,
that the virus no longer has new hosts to turn into viral factories.
Now, if we don't have a vaccine and we were to let this infection rage through
all million people in the United States,
we would see with the death rate of .%, . million deaths in the United States,
and I'd say that's a lower end estimate.
So herd immunity is a really deadly concept.
Now, I want to jump over here to this map of the United States.
And this map shows the severity of the outbreak of SARS-CoV-2, the pandemic in
each county across the United States.
So green counties don't have very serious pandemics.
And you can see they're not very many of those, and they're pretty rural places.
Yellow and orange means that the the pandemic severity is increasing.
And red means that the county has a severe outbreak of SARS-CoV-2.
So we're up here in Montana. Let's take a closer look. We've had , confirmed cases.
And on December th, we reported new cases.
And you can see that those cases are, for the most part, around population centers
in Montana.
So up in Kalispell, out of Missoula, over in Helena, Great Falls, Bozeman here
in Gallatin County, and then Billings.
But there are some counties where the outbreak is more serious. And then there's
some counties where there aren't that many people.
And we're just not seeing that many cases. To date in Montana, we've seen deaths.
That number has gone up quite a bit recently.
And if you look so at this purple sorry, pink arrow shows, it shows you when we
went into lockdown last spring.
And you can see there weren't that many cases, but it was a good thing we locked
down because we didn't know that much about the virus.
Now, you can see in the summer we had more cases every day.
And as we move through the fall, we're seeing more and more cases every day.
So we see a lot of daily new cases. And so, unfortunately,
what that means is that the number of deaths and the number of hospitalizations
in Montana is going to go up in the weeks to come.
But it doesn't have to be that way. Now, there's there's one way to stop COVID-19,
and that's with science.
And and that's actually one of the most amazing things I think we'll see in our
lifetime has been the development of a vaccine for COVID-19 when in under a year.
And there are currently seven promising vaccines that have been approved for early
or limited use.
And those will go to health care workers first.
And we'll probably see those vaccines start to get rolled out in the next couple
of weeks here into the early part of next year.
But those vaccines won't be widely available until later in the spring.
April is a month that I've heard thrown out as a current estimate for widespread
availability, but it could be slightly earlier or slightly later.
It's hard to get vaccines to million people.
So in the meantime, the number of people that die and the number of people who
get seriously sick is up is going to be determined by how we respond.
Now, this outbreak is largely spreading through young people.
And so we're going to have to stop COVID-19 the old fashioned way. And I don't
mean the way they tried to stop the bubonic plague in the Middle Ages,
in Europe, in these outrageous costumes with wands and bird beaks and long robes.
I mean, just making simple behavioral changes at one of the behavioral changes
we can make is by adopting this thing called pods.
So a pod is a group of people that you decide you're not going to socially distance
from and you're not going to wear a mask around.
And so in this population, we have nine people and three pods a blue pod, a purple
pod and a green pod.
And so I'm going to go through two scenarios here.
One in which there's COVID-19 spread throughout the community and one in which
COVID-19 spread is limited.
So in this first scenario where there's lots of COVID-19, someone in the blue
pod is infected with SARS-CoV-2.
Because they're in a pod with these other blue people, they are going to spread
the infection.
Now, remember, there's that window before you start to feel that sick where you're
contagious.
And so it's possible that if the the blue and the purple pods decide to meet up,
and because they've been careful,
they feel like they can take the risk of meeting up in person for a cup of coffee
inside.
So they end up sharing air, showing respiratory droplets,
and then this purple person becomes infected and the purple person will quickly
spread the infection to the rest of their pod.
Now again, remember this tricky pre-symptomatic before they start to feel sick.
Window where you're still contagious.
If someone from the purple pod meets up with someone from the green pod and they're
also unmasked and not socially distancing,
then the green person is going to spread the virus to the green pod.
And because we know that about two out of ten cases lead to hospitalizations or
death,
we can expect that in this population of nine people, at least one person is going
to get a serious form of the disease.
What's sad is that it didn't have to be this way. There are a couple of really
simple things that we can do to reduce the spread of
SARS-CoV-2 and reduce some of the community risk of hospitalizations and deaths.
And so these behaviors are pretty simple.
So in this scenario where people are a little more careful and they adopt these
behaviors, the blue pod still gets infected because they're a pod.
But because they're taking this pod thing seriously and they decide to only meet
up with the purple pod outside socially distanced,
they can't spread the virus through their respiratory droplets to the purple person
because respiratory droplets don't travel more than six feet.
And so the purple person isn't going to bring the virus back to their pod or say
the blue person works in a grocery store as a cashier next to the purple person,
and they're both wearing masks, even though they work next to each other and they're
wearing effective masks.
Not all masks are created equal. There's a link on the next slide where you can
do some research or feel free to ask me about that.
But they're wearing a good mask, let's say an N mask that stops most of the virus
particles from being exhaled.
And the purple person is wearing a mask which protects them from inhaling viral
particles.
And so even though they're working together, the purple person doesn't bring the
virus home.
And then because everyone's being careful, the purple and green pods meet up.
Or maybe someone else from the purple pod works with someone from the green pod.
They're masked up, they don't spread the virus.
So in this scenario, only three people get the virus and no one gets seriously
ill and has to be hospitalized and no one dies.
And what it came down to was a really simple idea. Remember, viruses need hosts
to replicate.
They need a cell to turn into a viral factory.
So the really simple idea is this don't be a host.
And there are five things that you can do to dramatically reduce the likelihood
that you'll be a host.
The first is to make a pod of people you live with and people you trust and then
avoid gatherings with people outside of that pod.
And if you do have to work next to someone outside of your pod or you want to
go for a walk with someone outside of your pod,
wear a mask while you do so, and make sure to socially distance.
So that means stay more than six feet apart. And then when you come back from
public places, make sure to wash your hands.
It's not that complicated. It's these five very simple behaviors, and they'll
make all the difference.
So with that, I'm going to wrap things up with a couple of links for staying informed.
I think that's another way to stop. The spread is know when the virus is spreading
and adjust your activities accordingly.
So I check my county health department website. I also check the Montana numbers
at this link and I look at the national numbers.
I particularly like the Johns Hopkins and the COVID-19 Act now dashboards and
your teacher will have a copy of this presentation.
And so if you want to get these links from them to check them yourselves, please
feel free to ask.
There's also great guidance from the CDC about masks.
You can see some of the research that's being done on masks. I recommend checking
out this page.
And with that, if I am going to be talking to you after you watch this video,
I'm looking forward to our conversation.
If I'm not going to be talking to you, but you'll be talking to one of my colleagues,
I'm jealous.
I really have a ton of respect and admiration for my colleagues.
They know a lot about viruses and don't be afraid to ask them questions about
their lives more generally as scientists at a research university here in Montana.
I'd actually encourage that. We are all really excited to be in the field of biology
doing science, and we'd love to share that excitement with you.
And if you have any further questions, also, don't be afraid to email us at our
Gmail account.
Montana Science Outreach at gmail.com. So thanks for tuning in.
I hope you found this presentation informative and I look forward to future conversations.