This year,
Carnivale is different.
The flu that had killed 15,000 in Rio is gone
but its spirit lingers.
Float crews adopt macabre themes taken from the height of the outbreak.
There's the block of the holy house,
playing off a popular euphemism for the hospital.
Behind them,
parades the block of the midnight tea...
...named after a rumor that doctors killed terminal flu patients with opium overdoses.
Street cars pass,
decorated with tea pots and cemetery gates.
A few months before,
the same street cars
had collected the city's dead.
[Opening music]
The third wave of the pandemic kept killing until 1920,
but it was clear that the worst was over.
Humans had done little to stop the virus.
Instead,
it simply ran out of fuel.
Those who caught it became immune
and it spread across the globe so fast...
...infecting so many people
that herd immunity began to protect those who escaped previous waves...
...but there were still flare-ups.
On November 11th,
1918
The news broke:
an armistice.
The Great War was over.
People flooded the streets
ignoring bans on public gatherings...
...and in each city
a new wave of infections followed the impromptu celebrations.
The same would happen again and again on a smaller scale
as loved ones gathered to welcome returning soldiers home.
There were still outbreaks,
still deaths...
...but everyone could see it was trailing off.
The horror
was past.
All that remained was to count the cost,
a project that continues to this day
In the years after the pandemic
researchers initially estimated the disease had killed 20 million people
Modern estimates have increased that number to 50 million
Though because statistics aren't available in the worst-hit regions
like India and Russia,
the final number may be twice as many
According to modern estimates, it killed 17 to 20 million in India...
...perhaps 4 million in Indonesia...
...possibly a million in Russia...
...400,000 in France...
...and 390,000 in Japan
In the United Kingdom, it sickened 1/4 of the population
and killed up to 220,000
In the U.S.,
it took around 675,000.
More than the Civil War...
...and killed 16,000 in Philadelphia alone
But for a disease that killed so many,
it's hard to point out direct consequences.
In fact, the flu seems to have worked in tandem with the war,
each magnifying the effects of the other
In the 1920s, a wave of political unrest swept countries around the globe
This was because of the war
but also because the flu had revealed
deep inequalities,
especially in colonial rule
Post-viral fatigue from flu infections
probably contributed to the depression and listlessness that took hold after the war.
Yet despite the heavy toll the flu took
and the heroism of medical workers that died fighting it...
...there's still no monument commemorating the event
other than plaques marking mass graves
Textbooks mention it
but usually just in passing
We chose not to remember,
which is why some have christened it
The Forgotten plague.
There are theories why society chose to forget the flu.
Perhaps it came and went so fast
that people simply remembered it as part of the war
Or it's possible that focus on the war
and inability to see the big picture
meant that society never really absorbed what happened
But keep in mind,
it also hit a generation that was just more
used to epidemics...
...in a time where mass death
may have been less shocking
Conversely,
some have argued that the flu was so traumatic
families formed unspoken agreements
never to discuss it
The memories that did endure were intensely personal:
lost parents,
lost siblings,
friends gone too soon,
families impoverished
when their breadwinners died
In some cases,
soldiers came back from the trenches to find their entire family wiped out
Ask your family
and you might find a story of your own
Generations later
the trauma still lingers
Yet apart from Katherine Anne Porter's Pale Horse, Pale Rider,
there was no explosion of novels about flu
as there were about the war.
It was a more difficult subject
It's faceless enemy more challenging to portray than the man-made terror of the trenches
But Porter wasn't the only notable person to suffer from the flu
In fact,
it infected so many famous people that it raises a chilling question:
How different would our world be
if even one of them had died?
Among the ill were President Wilson,
British Prime Minister David Lloyd George,
Gandhi,
Kaiser Wilhelm,
and General Pershing
A generation of notable artists
caught it as well
including T. S. Eliot
and a young ambulance driver named Walt Disney
Franklin Roosevelt contracted it while sailing on USS Leviathan
Then there are the people we did lose:
the president-elect of Brazil
and Austrian painters
Egon Shilla
and Gustav Klimt
Lenin's right-hand man succumbed,
clearing the way for his replacement
Josef Stalin
And In New York,
the flu killed an obscure German immigrant...
...allowing his son to cash in his life insurance and expand the family's real estate business
His name
was Frederick Trump
You might be familiar with his grandson
But the flu also drove scientific discovery.
Doctors developed new surgical techniques and procedures for disease containment.
It likely sped up the civilian world's adoption of ambulances.
The desperate vaccines
produced during the pandemic,
cocktails of antibodies from every bacterial doctor suspected...
...were the predecessor of today's combination vaccines
like Diphtheria-Tetanus-Pertussis
Nurses, who bore so much of the burden,
won new confidence and respect for their profession
Increasingly, their discipline became more than serving as doctors assistants...
...and the flu helped them be seen as professionals in their own right
Many cities and nations,
caught off guard by the crisis,
established new health departments...
...and organizations to monitor disease
It helped push the idea of national health insurance
and government provided medicine...
...and it drove research
By the 1930s, researchers were crafting effective flu vaccines
And many who battled flu would go on to do great things
Anna Williams nurtured an entire generation of female researchers
FDR eulogized Welch via radio
And remember Oswald Avery,
the guy Welch tasked with finding Pfeiffer's bacillus
and who helped develop the pneumonia serum?
After the war, he returned to researching bacteria,
trying to discern how a bacteria without a hard coating...
...transformed into a bacteria with one
After laboring for 20 years,
he finally found the substance that caused the change:
That's right.
Avery discovered that the purpose of DNA is to carry genetic instructions
Today, he's considered a pioneer of modern genetics
The flu also drove research into Pfeiffer's bacillus,
which many still believed caused flu
After working in a military hospital during the war,
one Scottish doctor devoted his life to studying microbes
One day, he accidentally left a culture of it out for the night
When he returned the next morning...
...he found a strange mold growing on it that killed any bacteria it touched
That man was Alexander Fleming.
And the mysterious mold?
It was penicillin:
the first wonder drug and probably the most consequential discovery of the 20th century
Even today,
the 1918 flu remains a subject of study for researchers
In fact, over the last several decades, researchers and epidemiologists
have started to make breakthroughs on the 1918 flu
Helping us better understand what happened
so we can combat the next great pandemic
Researchers still don't know where the flu emerged
There are way more theories than we portrayed
But we can now name the culprit
In 1998,
researchers obtained a lung sample from a frozen grave in Alaska
and confirmed what many suspected:
The 1918 flu was H1N1,
an avian strain...
...new then
but is less dangerous now that our immune systems have had a century of exposure
They've also begun to unravel the pandemics mysteries
For instance, we now suspect that it killed young healthy people precisely because they were young and healthy
Those patients that turned blue?
They probably weren't killed by the flu at all
but by their own immune systems
Once infected,
victims immune systems triggered a massive inflammatory response
known as a cytokine storm
But instead of neutralizing the flu,
this enormous release of disease killing cytokines...
...filled lung sacks with fluid
and inflamed them so much they couldn't absorb oxygen
But the greatest lesson of the flu pandemic
is that flu can't be ignored
We don't shrug off new flu strains anymore
In fact, many health organizations
monitor both human and animal strains...
...predicting the dominant variety each season and creating vaccine ahead of time
If a new strain does arrive,
we'll be much more prepared than doctors were in 1918
We have electron microscopes,
antivirals,
vaccine labs,
and tested containment plans
But a vaccine would still take months to produce
Meaning, we'd start
by using the same measures they did a century ago:
voluntary quarantine
banning public gatherings
staggering work hours
In fact, as Rob researched these episodes
the city where he lives,
Hong Kong...
...closed schools to prevent a seasonal flu outbreak
and killed birds that tested positive for avian influenza
A century later,
the battle against the 1918 flu and its offspring continues
So seriously,
GET YOUR FLU SHOT!
From an actual medical professional and not a
animated cat
[Ending music]