How COVID-19 human challenge trials work -- and why I volunteered | Sophie Rose

[Recorded on October 26, 2020.

COVID-19 vaccine development

and ethical considerations around human challenge trials

are constantly evolving.]

In April 2020,

I made what many perceive as a risky decision.

I volunteered to be deliberately infected with COVID-19.

This infection would be part of what is called a human challenge trial,

where young, healthy people are given a vaccine

and are deliberately exposed to the virus that causes COVID-19.

These trials help researchers figure out more quickly

if a vaccine is working.

I think this research is crucial,

because today, I'm going to speak to you for six minutes.

In that time,

roughly 1,250 people will be confirmed infected with COVID-19.

Twenty-one people will die.

And then this pattern will repeat hour after hour and day by day,

until we're able to vaccinate most of the eight billion people

affected by this global crisis.

Scientists have been working around the clock

to make those vaccines a reality.

But what should we do when the human cost of waiting for those vaccines

is rising by the day?

This is where human challenge trials come in.

They're different from the traditional phase three vaccine trials

taking place now,

where people are given a vaccine or placebo

and asked to go about their everyday lives.

Here, researchers have to wait to see how many people in each group

become infected.

Until enough of them get sick,

we don't have enough data to know whether a vaccine is working.

Finding an effective vaccine with this method

can take months or sometimes years,

and it requires thousands of volunteers.

A challenge trial works faster

because researchers control exposure,

instead of waiting for people to get sick.

So instead of a year,

we could know in as little as a month

whether a vaccine seems effective.

Instead of thousands of volunteers,

a challenge trial relies on just 50 to 100.

Because we know for certain

when people are exposed and develop disease,

these trials also allow us to gather data

about the early stages of infection and our immune response.

This data is impossible to gather in any other way,

especially for people who become infected but never show symptoms.

This knowledge is important for designing policies

that limit COVID-19 transmission.

The time saved translates into precious months' head start

on manufacturing,

getting us more working COVID-19 vaccines faster.

These trials are useful --

even though recent phase three results sound encouraging.

The arrival of the first vaccine is going to be a monumental breakthrough.

It just isn't quite the fairytale ending we're all hoping for.

We're going to need multiple vaccines,

because we just don't have the infrastructure needed

to immunize all eight billion people on the planet with just one kind.

Each type of vaccine requires its own special process and equipment

to make, store and deliver it.

If we had multiple working COVID-19 vaccines,

we could make use of all of our equipment at the same time.

Some of the leading candidates need to be kept extremely cold

before they are delivered to people.

This can be really hard,

especially in countries where there isn't reliable electricity

or a secure method to store them.

Scientists have been using human challenge trials

for hundreds of years.

They've sped up the development of vaccines against typhoid and cholera,

and they've helped us better understand how immunity develops

to things like the flu, malaria and dengue.

We've even used them for other types of coronavirus before.

There's been a lot of debate

about whether challenge trials are too risky.

I happen to think that those risks are worth taking.

A challenge trial would only recruit young and healthy participants --

think between the ages of 20 and 29.

Fewer than one percent of people in that age-group

need to be taken to hospital after becoming infected with COVID-19.

So it would likely be even lower in a challenge trial,

because researchers check to make sure

that participants have no preexisting conditions.

The risk of a young healthy person dying of COVID-19

is around five thousandths of a percent.

That means for every 100,000 20-year-olds who become infected with COVID-19,

about five die.

If I were to give birth in the United States,

my risk of dying would be higher than that.

Or you could choose to think about it this way.

If my little sister needed a kidney,

I wouldn't hesitate for a moment before I offered her mine.

And if I can take on that risk to benefit a loved one,

it makes sense to allow people to take on a similar risk

to speed up the development of a vaccine

that would benefit not just their loved ones,

but everyone around them as well.

There's a lot we still don't know,

especially about the long-term effects of COVID-19 infection.

I volunteered despite that uncertainty

because like many of you, I feel frustrated

knowing that hundreds of thousands of people are dying.

And that's without mentioning the millions more who are struggling

as measures to stop the spread take a toll on their physical,

emotional and mental well-being.

It turns out I'm not alone in feeling this way.

Since May, over 39,000 people from across the world

have volunteered to participate in potential COVID-19 challenge trials

through a nonprofit I helped found called 1Day Sooner.

We advocate for challenge trial participants

and have been encouraging stakeholders to begin preparing for these trials.

As early as May,

when challenge trials were still being considered

for their role in the fight against COVID-19,

the World Health Organization cited 1Day Sooner

as an example of the kind of public engagement needed

to run a challenge trial.

In mid-October,

the UK government formally announced their intention

to conduct a challenge trial at the beginning of 2021.

It is clear that the COVID-19 pandemic is a global crisis.

It has inspired record-shattering innovation,

and it has highlighted the heroic acts of many frontline workers,

but is has also taken a catastrophic toll.

The arrival of each new vaccine brings us one step closer to rebuilding.

But the true global solution

lies in those vaccines being in the hands of people all over the world.

Challenge trials could be a part of that solution.

Thank you.