William shatner: From the plagues of egypt
to the black death,
smallpox,
cholera,
and the spanish flu,
humans have repeatedly faced contagious diseases
that have the power to change the course of history.
We like to think that modern medicine
can protect us against almost everything, but...
Is that really true?
Or are we destined to face a future
of ever more potent illnesses
that attack without warning
and can bring civilization to its knees?
Well...
(sucks air through teeth)
...That is what we'll try and find out.
♪ ♪
shatner: News reports surface that a new,
highly contagious disease first discovered in wuhan, china,
is spreading like wildfire.
In a matter of weeks, the lethal virus--
known as "coronavirus" or "covid-19"--
sweeps the globe.
On March 11,
as the number of infections and deaths
continue to climb,
the world health organization declares
that the outbreak has become a worldwide pandemic.
Raj dasgupta: What separates, clinically,
coronavirus from other common viruses such as influenza
is that it knows how to hide itself.
It has what we call a period where you could be asymptomatic.
That means without symptoms.
That's a chance to pass that virus to other people,
keeping the disease going on and spreading.
Most of the time, when you wait for these symptoms,
you've already missed it.
Shatner: In the wake of the harrowing effects
of the coronavirus outbreak,
scientists have been compelled to reexamine
the nature of viruses themselves.
Viruses are very mysterious,
because you can't see them.
You need a very powerful microscope
to be able to see them.
And we didn't even know that they were around
until relatively recently.
Kirsten fisher: A virus is essentially a bit of nucleic acid,
either dna or rna,
encapsulated in some sort of coating. Right?
So it needs to-- it needs to get into another organism
and then essentially hijack that organism's cellular machinery
to make more copies of itself.
Dasgupta: It needs to
actually take over another living cell.
And whether that's the living cell of a human,
animal,
plant or even a bacteria,
it needs that.
It's making more and more viruses
till that cell is not needed anymore.
Fisher: A virus relies on either
direct transmission through sneezing or coughing
or touching, um, a viral particle
from a person who's expelled it.
Or they rely on a mosquito or some other organism
to be transmitted between people.
And so the density of people
will facilitate quicker spread of viruses,
especially if it's, um, relatively contagious
and-and easy to-to transfer from one person to another.
Shatner: According to experts,
the origins of many viruses
remain shrouded in mystery.
Dasgupta: It's so difficult
to determine the origin of viruses because,
when you want to study that virus,
you have to separate what is the natural history of that cell.
So one of the important things
that epidemiologists are looking at right now is,
what did we learn from the past?
What should we be looking at?
Where should we be looking?
Some of the earliest records of plagues
are found in ancient india,
china, the middle east,
and they talk about plagues occurring
before the very first civilization,
around 3200 bc.
Shatner: Throughout human history,
there have been accounts of devastating afflictions
that defied understanding at the time they happened.
But perhaps a closer examination of these plagues
will provide some lessons about infectious diseases
and how they begin.
(gull calling)
emperor justinian sits atop a powerful throne.
But lurking in the shadows is a hidden enemy
about to consume his kingdom.
A plague
started by a bacteria
comes out of the east
and infects.
This simple bacteria
ended up killing
almost one half the population of the entire old empire.
With that type of death toll,
the economic and social ramifications
were catastrophic.
Everything that justinian had tried
was now collapsing.
His military collapsed, his economy collapsed.
And everything that he tried to do
was of no avail.
(coughing)
fisher: Justinian plague is caused by a bacterium,
yersinia pestis.
It can either enter humans directly, um, through--
from saliva or-or coughing.
It usually manifests itself
in terms of swelling of the lymph nodes.
The skin turns black and basically dies.
And then there's a progression of fever
and chills and eventual death.
Tzadok: As justinian's empire was collapsing and breaking
and his military strength was waning--
because the science of medicine in those days
was far more primitive than we have today.
People cry out, "why?
Why is this happening?"
shatner: The plague of justinian, as it became known,
ultimately killed an estimated 50 million people.
The vast byzantine empire was crippled
not by an invading army
but by an enemy they could not see and did not understand.
At the time,
since the existence of bacteria and viruses
had not yet been discovered,
many believed that the invisible force that caused the plague
was god himself.
It was a belief that was widely accepted,
because people would read in the bible
about how pestilence from the past
had been created by the hand of god.
Whenever humanity is infected
by something greater and beyond human understanding,
it has always been psychologically understood
to be an expression of the wrath of god.
We have in the book of exodus
the famous ten plagues of egypt.
Moses had come back after seeing god on the mountain
to free the hebrews from slavery.
He went before the pharaoh and asked to let his people go.
Of course, the pharaoh said no.
Therefore, the hebrew god sent a number of plagues through egypt.
Tzadok: The bible stories are clear.
The order of the plagues are well-documented in the bible.
We know, of course,
that there was the turning of the nile into blood.
There were the frogs, the lice,
the pestilence and, of course,
the great plagues of the three days of darkness
and, of course, the death of the firstborn.
Bidmead: The biblical writer who is writing what happens
and is inspired by god
does say that the plague stopped
after the hebrews were finally free.
So, perhaps there was some divine intervention from god.
But we'll never know,
because miracles are very difficult to prove.
Shatner: Was there a higher power involved
that both started and ended the plagues of egypt
and the plague of justinian?
Perhaps more clues as to what causes devastating plagues
can be found by examining the disease responsible
for claiming more lives than any other.
Officials from the california odepartment of public health
alert residents that a woman has tested positive
for a dangerous and quite unexpected disease.
The bubonic plague,
otherwise known as the black death.
Dasgupta: Does the bubonic plague still exist?
The answer is... Yes.
And it's amazing
how, many centuries later,
you could say this with a calm voice.
What is the difference?
The answer is antibiotics.
We know that if you have symptoms early
that antibiotics can save your life.
Fisher: While it's not as prevalent anymore,
the plague is certainly still in circulation.
In the united states, right, in more rural areas,
where people come into contact with-with rodents
that might be infected with it,
it's still known to, like, crop up here and there.
The worst case of the bubonic plague that there was
was known as the black death,
in the middle of the 1300s.
And that wiped out
60% of all of europe's population.
Shatner: 12 trade ships arrive
from the black sea
and drift into the port of messina to unload freight.
As dockworkers
approach the vessels,
they discover a disturbing scene.
Dasgupta: The port master goes on board
to see the crew, and, to their surprise,
it was almost like there were zombies on the ship.
Gangrene fingers.
Big boils.
And if I saw
a crew that had black fingers
and boils, let's be honest:
It sounds like a zombie apocalypse.
The black death seemed to have been introduced
via the silk road,
which is a major trading route
in the early medieval period from central asia
where the bubonic plague regularly pops up.
Europe seems to have been largely unprepared
for this devastating event.
This is in the 1300s.
It went for quite a few years,
and whole villages and areas were wiped out.
And like many plagues, uh, people wondered why.
Dasgupta: These cities would get the plague,
and no one knew why.
And then we always have the advantage
of looking back on history and tracing.
Historians could look back and say, "wait a minute.
"all the cities with ports
"that do a lot of trading were infected.
And what were going to all these ports? Ships."
phillips: The black death
was spread by fleas that lived on rats.
And wherever these rats went, the fleas went,
and they bit people. That's what made them ill.
Christine colby: The flea would actually vomit the bacteria
onto the person's skin while biting them.
The disease spreads to the body's lymph nodes
and causes buboes,
which are infected sores
which get to be about the size of an egg.
And they eventually burst and expel bloody pus.
The body goes through
such horrific and gruesome transformations
that from the time you contract the bubonic plague until death
can sometimes only be a matter of days.
Shatner: During the middle ages, many believed
that demons were responsible for the black death.
-(coughs) -and people who were deemed
to be wicked or unworthy
were punished
in hopes of driving the demons away.
Tzadok: Many people believed
that the source of this plague
was caused by evil spirits,
witchcraft and the like.
The powers of the occult.
And this led many people
to seek out any type of expressions
of the occult, witchcraft and the like...
...And to root it out
in the attempt to placate god.
(screams)
shatner: Some were so convinced that the black death
was a scourge brought by evil spirits,
they were willing to scourge themselves.
One common occurrence during the time of the black death
was to see, uh, people that were called flagellants, which...
They were under the belief that they were being punished
by god for their sins, so they would publicly atone,
and they would March through the town square,
flogging themselves in the name of god.
(groaning)
thompson: This flagellation movement really exploded.
Whole towns flagellating themselves.
Those that didn't were accused of being with the devil.
Phillips: Something else that came from the black death was
the practice of selling holy relics.
When the black death was decimating europe,
the church were saying,
"come to us,
and we can cure you."
the bones of a saint
or something that had once belonged to a saint
kept in these churches. They were called relics.
And people believed that if they went there
or close to such relics,
prayed, that god may intervene
and protect them from the plague.
Now, they weren't curing anyone,
but people were still flocking to the churches
just on the hope that they could be cured.
Dasgupta: So, when we talk about the many lives
that were lost during the black death,
I think about a horror movie.
Shatner: Historians estimate that the black death
wiped out anywhere from 50 to 200 million people,
at least a third of europe's population.
So it's little wonder
that most people thought that something so destructive
must have been some kind of punishment from god.
But today, we have a much different understanding
of this disease.
Gronvall: We call it the black death,
but it's-it's a bacteria called yersinia pestis.
But it's not as dangerous as it was then.
Now we have antibiotics.
We can detect it.
You know, you can treat it.
In any case,
yersinia pestis is still around today,
which begs the question,
is it possible
to actually kill off a fatal disease
once and for all?
Perhaps the answer can be found
by examining a deadly plague
that, believe it or not,
has been infecting humankind
for more than 10,000 years.
Shatner: The valley of mexico.
Spanish conquistadors led by hernán cortés
arrive at tenochtitlán, the capital of the aztec empire,
bearing dreams of conquest
and an insatiable desire for gold.
But they also brought with them a lethal, infectious disease.
Thompson: Smallpox is introduced
into the americas very dramatically
at a specific point in time
and alongside the european invasion.
This is a tremendous sort of clash of civilizations,
the likes of which the world had never seen before
and will never see again.
The single most deciding factor
as to why native american civilizations fell so rapidly
was the introduction of smallpox.
Fisher: So, smallpox is a virus.
It causes these sort of irregularly spaced,
pustule-y skin lesions
and had a devastating effect
on-on native americans, um, in the new world.
Gronvall: In europe, most people had experienced smallpox.
They had the scars,
or they had it as children.
But there was no immunity in the new world.
There was no immunity among kids.
There was no immunity among adults.
And so, when this new disease came,
everybody was vulnerable.
And so it spread like wildfire.
Shatner: Although the exact numbers will never be known,
many experts estimate
that a staggering 95% of the indigenous population
would eventually die from smallpox.
But what's even more chilling
is the fact that smallpox ran rampant
for thousands of years.
Gronvall: I am astounded
by how far back smallpox goes.
For most of human recorded history,
we believe it's the same strain
that was infecting one person after another,
this human chain of infection.
The egyptian pharaoh ramses v had scarring on his face
that's consistent with smallpox.
Shatner: It is estimated that smallpox has killed
between 300 and 500 million people
in its more than 10,000-year existence.
Which begs the question: How did we finally beat it?
Well, it just so happens that the cure for smallpox
was discovered in a small english village in the 1790s.
Gronvall: In the late 1700s, doctors were noticing
that milkmaids did not seem to be affected by smallpox,
and their complexions remained unscarred.
And people were starting to make that connection
that there might be immunity from catching
a different kind of pox virus, cow pox.
So milkmaids were exposed to the cow pox virus,
probably got infected,
and were then immune to smallpox.
Edward jenner was an english physician,
and decided to test this observation,
and took a piece of an ulcer from a cow
that was infected by cow pox,
and gave it to an eight-year-old boy.
And then, a little bit later,
gave this little boy a dose of smallpox.
Fortunately, the eight-year-old boy did not develop smallpox
and was actually protected.
Because it wasn't, like, a direct viral intake,
you would get, like, a slightly lesser version of the disease.
But because you had been exposed to it,
you would, of course, then have immunity.
So it was probably the first instance
of a crude version of vaccination.
Shatner: As it turns out, edward jenner's revolutionary experiment
is remembered today for its inspiration,
its sheer audacity
and because it provided a new defense
against infectious disease,
which we now refer to as "the vaccine."
the word "vaccine" comes from the virus name "vaccinia,"
which was the virus that was the cow pox-derived virus
that left people immune to smallpox.
Vaccines prevent disease,
and some vaccines can last for decades,
and some vaccines need to be given every year.
For smallpox, people had to get vaccinated every ten years.
Shatner: Vaccines are humanity's single greatest weapon
against plagues.
Rooted in science and not superstition,
they provide a powerful way to fight outbreaks.
Gronvall: The last naturally occurring case of smallpox
was identified in 1979, and in 1980,
the world health organization declared
that smallpox was eradicated.
So no longer spreading from person to person.
Eradicating smallpox was the biggest public health victory
in the history of the human race.
Shatner: The eradication of smallpox is the most famous use
of a highly-effective vaccine,
but there are some diseases that are harder to cure.
Michio kaku: There are viruses
for which we have no vaccines at all,
because they mutate too rapidly.
And so, because viruses mutate,
there's a certain limitation to what you can do with vaccines.
Dasgupta: The minute you get too confident,
and you think that we defeated mother nature,
somehow, it always finds a way to come back.
Shatner: Vaccines are one of mankind's
greatest scientific triumphs.
But not all medical recoveries
can be easily explained by science.
Sometimes, the body's reaction
to an infection is so bizarre and so inexplicable
that it can only be described as...
Miraculous.
Shatner: July 4, 1863.
Gettysburg, pennsylvania.
On the morning after the bloodiest battle
of the civil war,
thousands of dead soldiers lay strewn
across the blood-soaked farmland.
But while the brutality of the civil war is well-documented,
approximately two-thirds of the more
than 600,000 deaths in the war
weren't caused by injuries sustained on the battlefield,
but rather... By disease.
Fisher: The civil war represents
the last major conflict that, um, that humans experienced
um, before the, sort of, the inception
or the origins of germ theory.
You can imagine the conditions
that soldiers live in, crowded together,
substandard sanitation.
In some cases,
open wounds that aren't being treated correctly.
Wynn: It's really gross.
Everything smells terrible.
Uh, these doctors aren't washing their aprons.
They can't explain where they're getting these diseases from,
how they may be spreading it.
Shatner: As uncontrollable infections ravaged
both union and confederate encampments,
soldiers and their doctors debated the cause
of their afflictions.
Many came to believe that the air itself was poisoned.
Dasgupta: When we talk about
some of the deadliest viruses that we know,
some of them get transmitted by respiratory droplets, the air.
When you cough, when you sneeze, just by talking.
So maybe they weren't too off by saying the air is bad.
Shatner: In the mid-nineteenth century,
little was known about disease control
or preventing the spread of germs.
But as the scope of the war widened
and the ferocity of infectious outbreaks resulted
in even more horrific causalities,
doctors were forced to expand their knowledge of diseases
and how to contain them.
Wynn: They realize that
maybe a barn isn't the best place to be doing
amputations and open surgeries.
So, as the war goes on,
there's beginning to be an understanding
of what medicine should be.
Things like triage,
things like an ambulance system, hospitals--
these are all established during the civil war
in the united states for the first time.
Shatner: In many ways, the civil war marked the beginning
of medical science as we know it
and the end of mankind's
superstitious attitude towards disease.
But there is one event on the battlefield
that medical historians still struggle to explain to this day,
because it simply defies understanding.
April 7, 1862, hardin county, tennessee.
Union and confederate forces square off
in one of the bloodiest confrontations
of the civil war-- the battle of shiloh.
After two days of vicious fighting...
(yelling)
...More than 20,000 men lie dead or dying.
Wynn: So, ulysses s. Grant is the commander
of the union army at this battle.
He went out, and looked over the battlefield,
and he could see that there were so many soldiers who had been
wounded and killed that he could have walked across one side
of the battlefield to the other
without ever touching the ground,
walking from body to body to body.
Shatner: As night falls over the battlefield,
many injured soldiers lie helpless,
hoping to be rescued before their wounds become infected.
What happens next is one of the enduring mysteries
of the civil war.
Wynn: Soldiers are out between the lines,
wounded during the course of the battle.
It's cold at night. They're out there shivering.
And they happen to look down at their shattered arm or leg,
and they notice this soft, faint, bluish-greenish glow
seeming to come off their wounds in the darkness.
There was a connection that was being made amongst the soldiers
that those who experienced this glowing wound effect
seemed to have better outcomes
when they went back to the field hospital, and it seemed
as though their wounds may not have been as infected.
Bidmead: They termed this bluish-green glow
angel's glow. Why?
Because, to them, it looked like a halo.
Mystical light surrounding them.
So, it was a way of them thinking that god
or the angels were protecting these particular soldiers.
Shatner: Was the so-called angel's glow
a type of divine intervention
that somehow protected certain soldiers from deadly infections?
Perhaps. But recently, a new theory has surfaced--
one that suggests this phenomenon
may have had a more conventional explanation.
It wasn't until many years, like 150 years later,
that a 17-year-old high school student visited shiloh,
and he decided for his science project
to research bacterium that glows.
And they were able to find out that there was a bacteria
that would emit some sort of parasitic worm.
It would get into the veins, and then it would glow.
Shatner: Could the angel's glow
really have been a sign of a type of bacteria,
rather than guardian angels?
And if so, could this bacteria have actually been responsible
for saving the lives of the wounded soldiers?
Presumably, what happened with those soldiers
with the angel's glow
is that those bacteria were actually infecting their wounds.
And because those bacteria exude a lot of antibacterial
and antimicrobial compounds, they actually reduce the level
of infection in the soldiers
that they, that they, uh, colonized.
Shatner: The bacteria theory
is the best scientific explanation we have
for what caused the angel's glow.
If this incredible theory is true,
then it seems that some forms of bacteria
can actually help us in the fight against disease.
But the soldiers whose lives were saved
at the battle of shiloh believed that what healed them
could only have been sent from heaven.
Wynn: We can't know what those soldiers experienced
out there on the battlefield between the lines.
They're in the dark, they're suffering from shock.
Who's to say that they didn't experience that
or that they did experience that?
Guardian angels, reaching down to comfort
and even cure dying soldiers during the american civil war?
To some it sounds like pure fantasy.
But to others, especially those
who've had their own close calls with death,
there's no doubt that such a notion is entirely plausible.
Let's face it: When dealing with deadly diseases,
it's hard to be certain of pretty much anything.
Not only do we often know very little
about how to cure an illness,
we know even less about where an illness comes from.
For instance, what if I told you
that what we commonly refer to as the spanish flu
didn't come from Spain at all, but from a remote army base...
...In kansas?
Shatner: At the height of world war I,
more than 50 years after the end of the american civil war,
soldiers from more than 30 nations are engaged
in trench warfare all over europe...
...And a new, unexpected enemy emerges...
-(coughing) -...The spanish flu.
Wynn: Europe is awash
in the influenza virus.
They had a massive outbreak of influenza,
and these soldiers serving at the front lines
are directly impacted on both sides of the conflict.
-(coughing) -the symptoms were pretty horrific,
and so these soldiers were not capable of performing
their duties, and many of them actually die of the disease.
Gronvall: We're used to the flu, but the 1918 flu
had more severe symptoms and lingering effects.
When the flu first started spreading,
their skin turned blue.
They just had no oxygen in their blood.
It was not uncommon for people to lose all their hair.
It was not uncommon to have neurological side effects.
Wynn: The 1918 influenza strain
caused an incredibly high fever, it caused coughing.
In many cases, patients' lungs would fill with fluid
as this virus is taking over their body.
That would cause an immune system overreaction
and they would essentially drown.
Shatner: Medics on the front lines,
prepared for the ravages of war,
look on in horror as young, healthy soldiers
begin to die within days,
or even hours of showing symptoms.
The spanish flu was caused by, um, an h1n1 influenza virus.
And the particular strain of the h1n1 virus
was a little unusual amongst influenza viruses
in that it was much more contagious, it was much easier
to expel and spread between people.
In 1918, we still really were
sort of incapable of stopping its spread.
This was right at the end of world war I,
and so soldiers were, of course, kept in close quarters
and barracks together.
And then, also, people were sort of moving around the world
more than they probably normally would have been
sort of traveling.
Um, and so those were some of the factors
that caused it to spread really rapidly.
Shatner: Since finding a cure for a mysterious virus
in the midst of a world war is a difficult,
if not impossible undertaking,
both the central powers and the allied powers
decided the best course of action
was to downplay the threat posed by the disease.
In fact, the 1918 flu is called the spanish flu
not because it came from Spain, but because,
initially, Spain was the only country willing
to acknowledge its existence.
Gronvall: The reason we think of it as the spanish flu
is because Spain had a free press at that time,
and the rest of the world did not.
Spain was not involved in world war I,
and their king ended up getting the 1918 flu.
So it was a matter of national interest,
and most americans learned of the flu
from the spanish papers.
Shatner: The so-called spanish flu is estimated to have infected
one third of the world's population at the time,
roughly 500 million people.
But while the press created a lasting nickname
for the 1918 flu,
some researchers have suggested that it actually originated
in the heartland of the united states.
March 4, 1918.
Fort riley, kansas.
Before the so-called spanish flu outbreak was reported in europe,
a private at this remote army base in the united states
starts to feel ill.
Wynn: In March of 1918, an army private named albert gitchell--
he's a cook with the army--
he reports symptoms, so he goes to the hospital.
Uh, he's sick, he's-he's not feeling well.
He's got a bit of a cough, bit of a fever.
In the end, he ultimately goes in to work,
feeding all of these soldiers in this army camp.
In the weeks that follow, the members of this camp
come down with a pretty nasty flu strain.
And there are no other outbreaks similar to this at this point,
which suggests that this outbreak is starting
at that camp, and potentially with that soldier.
Colby: There were 1,127 cases just at fort riley itself,
and 46 people died.
So all these soldiers at fort riley are thinking
they just had a bad cold, or maybe even a mild flu.
They were eventually all put on trains,
which spread all over the country
going to various ports.
And then they were all shipped off to europe
to fight in the war.
Shatner: Many scientist now believe that army private albert gitchell
was the first man to contract the 1918 flu.
Gitchell spread it to his fellow servicemen
when he served them food.
And soldiers then were sent overseas
to fight in the war, and they unwittingly
spread the disease around the globe.
But of course that explanation is only a theory.
The situation fits the epidemiology,
the number of people who got sick afterwards.
But whether we will ever know for sure
who patient zero was,
or whether it absolutely came from kansas,
it's hard to be absolutely sure.
It's really hard to learn where any virus starts,
where any pandemic starts, because you're not recording
everywhere all the time,
and having the scientific tools in place
to be able to detect it.
Wynn: The great mystery of any of these pandemics
or public health crises is where did it start?
And, ultimately, why did it start?
And what were the circumstances that allowed that to happen?
It's the story of how we interact with one another,
and how we spread diseases amongst each other.
If you track that and you find that out,
we could prevent it happening again in the future.
Shatner: The spanish flu outbreak lasted for three long years
and killed an estimated 50 million people
before society finally developed enough collective immunity
for the virus to die out.
History shows us that no matter how lethal a disease may be,
humankind has always found a way to endure it,
whether by employing medical breakthroughs
or sheer patience.
But what kind of illnesses will we have to face in the future?
Could they be different than
what we've experienced in the past?
And might they come to our planet from another world?
Shatner: British astronomer sir fred hoyle
publishes a book titled astronomical origins of life:
Steps towards panspermia.
In it, hoyle investigates the controversial theory
of panspermia, which suggests that
life on earth did not originate here
but rather in space,
and that asteroids carried the microbial
building blocks of dna to our planet.
Kaku: You cannot dismiss the possibility
that maybe life came from outer space.
That we were seeded. Seeded by asteroids or comets
that then put their organic materials
onto the planet earth.
And so there's a new theory in astronomy that says that
the solar system is like a ping-pong game
with meteorites carrying microbial lifeforms,
going back and forth between venus, mars,
the earth and the moon.
This has given momentum to the panspermia theory.
Shatner: Some scientists have suggested that if the theory
of panspermia is true,
then it's possible that extraterrestrial viruses
could also travel here, bringing with them diseases
that would be much different
from the ones that exist on earth.
Michael dennin: When you think about the core elements
of viral plagues-- those are the four genetic codes,
dna or rna within a protein shell--
that's something that's easier to imagine being stable
deep inside an asteroid, and safe.
And so any sort of virus or plague,
you can imagine them starting from
one of these asteroid events.
A space plague is a leap into the unknown.
We have no way of knowing what kinds of dna,
or maybe a modified dna version exists in outer space.
We have never seen other kinds of viruses from outer space
that can infect earthlings.
So right now we simply don't know the answer.
Dennin: I think if a plague came from outer space,
just like the way some of the plagues we know
jump from animals to humans, suddenly,
any sudden change in the viruses
or bacteria that are attacking you as a human,
your immune system will not have a defense to, most likely.
These dramatic events, whether it's from space
or a sudden jumping from animals to humans,
are the reason these plagues can be so devastating.
Shatner: A plague from outer space?
While that may seem like a far-fetched notion,
it's a possibility that science must be prepared for.
Wynn: There are always these viruses out there,
these things that we can't explain.
It's important for us to always be vigilant, to be aware
and to have our public health authorities
always on the lookout.
So we can never put our guard down.
Dennin: Hopefully, the faster we are
and the better we are at bioengineering,
the faster we can make vaccines and countermeasures.
It's key to have them so that we can make ways
to protect ourselves.
Preparing for any disease is complex,
and it requires a lot of, um, mobilization of government,
public health, and the science to be able to figure out
what happened, and to prevent it from happening again.
To be able to halt transmission of this disease, whatever it is.
It becomes a detective story as well.
You need to figure out where it came from
and how to attribute the disease.
It's a mystery that our lives depend on,
and we need people to be working on that
and thinking about that.
Perhaps what makes deadly diseases so frightening
is that we never know when they're going to strike next.
And that uncertainty is also what forces us
to ask ourselves are we really safe?
Well, the truth is that only time will tell.
Which means that, at least for now,
these questions will remain unexplained.
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