- The flu sucks.
Every year it affects millions of people
and kills several thousand of them.
I'm talking about actual influenza.
High fever, cold sweats, constant body aches,
these B-role actors probably don't have the flu.
You can tell because they're wearing makeup
and if you have the flu you're too busy praying
for a quick death to put on mascara.
- I'm so sorry.
- Anyway, the flu is a right beast
and you can't beat it because it evolves too quickly
for us to develop a lasting vaccine.
But thanks to some snot from cancer patients
fighting the flu, we finally got a sneak peak
at how evolution works.
What we learned could change
how we view the entire universe.
Or maybe just help us make a better flu vaccine.
This is On the Fringe.
A show about weird ideas that just might change the world.
- Viruses like influenza have a very short generation time.
For humans a generation tends to be 25-30 years.
For a virus like influenza, it's less than 12 hours.
This is Jesse Bloom, an evolutionary biologist
at the Fred Hutch Cancer Center in Seattle.
He's super cool and super smart and everything,
but we're actually here to see one of his graduate students.
- My name is Catherine Chu, I'm a graduate student
at the University of Washington
and I study how viruses evolves.
I've been really interested in viruses
because they're some of the fastest
evolving things on Earth.
We usually think about that change happening
over really, really long spans of time,
like thousands or millions of years.
But I'm super interested in how living things can change
in much shorter amounts of time.
Just maybe days or weeks or months.
- The reason the flu is so difficult to beat
is the same reason it's great for studying evolution.
It evolves super fast.
So you make a vaccine to fight one strain of the flu virus
and before you know it, poof,
it evolves and you need a new one.
- For a long time I was kind of abstractly just curious
about this question of how much viruses could possibly
change within someone in the short time that they're sick.
But it seemed to me that this was something
that would just be really, really hard to study.
- For one thing, most people who get the flu
don't even go to the doctor, let alone have their mucous
tested to see if it has the flu virus.
Even then, it would only be a single data point.
It didn't seem like it was possible to study
how the flu evolved in one person over time
until her advisor made a random discovery.
- I was down in the coffee shop at the Fred Hutch
and I was talking to Steve Pergum who's in charge
of infection control for immunocompromised cancer patients.
I said you know, "What are you up to these days?"
and we started talking.
- He said, "You know, I'm having trouble getting samples
"about patients that have multiple samples
"in patients that have flu.
"If you have any ideas about where I could get that."
- Turns out Steve was sitting on a freezer full frozen gold.
If by gold, you mean mucous
from cancer patients fighting the flu.
Well most flu infections might last a couple of days,
the immuno-suppressed patients
at the Fred Hutch Cancer Center had flu infections
that lasted for months.
And there were samples from across the entire time line.
Catherine had all the samples she needed.
She began to sequence the RNA of the flu samples
and immediately had a surprising result.
Like really, really surprising.
The first set of samples that Catherine sequenced
showed that the flu evolved in ways that no one expected.
- I saw these two mutations that were almost perfect matches
with each other.
They arose within a couple weeks,
they made up about half of the viral population,
and then they kind of went away.
In that initial analysis, I realized
that there was a lot of evolution going on.
It was pretty complicated.
Something interesting was happening.
- By using deep sequencing techniques,
Catherine wasn't just seeing the average virus on a patient.
She was seeing all the different strains
and how prevalent each of them were.
Because she had multiple samples over time,
she could see how it changed over course of the infection.
She could literally see evolution.
Then she sequenced the samples from the other three patients
and that's when things got really weird.
- When she finally sort of put this data together
and she looked at these different patients
and she saw the same mutations appearing
in multiple different patients.
We saw the evolutionary processes in some ways
repeating itself multiple times,
that to me was kind of the eureka moment.
- Now, mutations are supposed to be completely random.
So it's very surprising to see several patients
each having the same mutations.
- These are four patients who are different from each other.
They're not giving each other the flu.
They have very, very complicated medical histories.
Very, very different infections.
And yet, starting from different viral backgrounds,
we see, in many cases, the exact same mutations occurring
and reaching high frequencies within these patients.
- Not only did these patients have some
of the same flu mutations arising independently
from one another, they also shared commonalities
with how the flu evolved globally.
The snot from these patients was a preview of
how the flu would then evolve out in the world.
Sort of like looking through a crystal ball,
except it's made of boogers,
and seeing a glimpse of the future.
Someday soon, this means we can expect better forecasting
for flu vaccines, but it also means
we have a new perspective on evolution as a whole.
It raises huge questions about how predictable
or repeatable any evolutionary process is.
But the most important take away is this,
a 20-something graduate student in Seattle
changed the way the world looks at evolution.
You're watching videos on the internet,
which is great for us.
Don't stop watching these videos, please God.