Press Room




Sue Desmond-Hellmann
Eliminate Dengue: A Case Study
Grand Challenges 2016: Precision and Preparedness for Public Health Emergencies
London, United Kingdom
October 25, 2016

I get to introduce a terrific session. You have a treat in store this morning.

Now, the Gates Foundation is a relative newcomer to the global response to public health emergencies.

Ebola – not long after I started as CEO - was really the first time that we had made a major commitment of financial and human resources to such an emergency, investing initially $50 million and pulling in staff to help the response.

The Ebola outbreak prompted us to think more about emerging threats.

My boss, Bill Gates, went on a mission to learn more about epidemics.

What he discovered he found very sobering.

He went on to give a TED talk and wrote a paper for the New England Journal of Medicine arguing that the world’s unprepared to deal with a disease that infects large numbers of people very quickly.

As Bill put it: “Of all the things that could kill 10 million people or more in the next decades, by far the most likely is an epidemic.”

But I’m optimistic.

I’m optimistic that we can prevent such a doomsday catastrophe from unfolding.

And I believe that part of the answer to preparedness lies in two things I want to talk about this morning: curiosity-driven science – basic science - and data sharing.

So, just before we get into our discussion, I want to make a pitch for both of those today.

First, curiosity-driven science.

History shows us that investments in basic research are the primary engine with which humanity has advanced.

When Jennifer Doudna tells the story about looking at CRISPR Cas9, she wasn't trying to cure cancer or solve genetic diseases, she was just trying to figure out how things work.

Her findings are very exciting – and the subject of a number of talks in this year’s Grand Challenges meeting.

We’re hearing more about the potential for CRIPSR to contribute new solutions.

But that’s for the future.

What it does show is that trying to figure out how things work is an important balance to trying to solving a particular problem.

Basic, curiosity-based discovery provides an understanding of nature, an understanding of biology, an understanding that is the foundation from which we can respond to diseases and health threats.

And that is, for me, how basic science becomes a global good.

You don’t always know when or how or in what way human problems will surface.

But the whole point of basic science is that you do know about fundamental factors that will increase the likelihood of success in your response - and that will speed things up.

Once you have recombinant DNA technology, a double helix, an understanding of how RNA and DNA works, knowing about how cell walls work, then you’re just so much smarter in using science to solve human problems.

Second, data sharing.

Science isn’t done in isolation, science is a team sport, a collective activity with each new discovery building on the past.

And I believe that we can do even better by sharing our findings, sharing data - and sharing them openly and promptly to accelerate our collective endeavors.

This is especially vital when we seek to respond rapidly to emerging crises.

When emergencies strike, it is critical that scientists and policymakers have quick, easy access to the best available data.

Rapid response relies on rapid access to quality data that leads to a more precise understanding of what is needed and what can be done.

And there aren’t many more powerful examples around right now of the benefits of both curiosity-driven science, matched with the kind of open data sharing that’s a hallmark of Grand Challenges, than the story of Wolbachia.

The Wolbachia story didn’t spring out of nowhere.

This is actually not new.

There was science on the fact that about 60 percent of the world's insects have Wolbachia.

And we know this about Wolbachia and insects because people wanted to how bugs work.

There’s this weird thing about them having this infection with bacteria and when scientists tried to understand that better we learned about the microbiome.

Long before we even used the term microbiome, knowledge was built up over decades and decades of research about the animal kingdom and zoology and entomology.

Based on this early science, this curiosity-driven science, as part of the original Grand Challenges in Global Health, the Bill & Melinda Gates Foundation made a bet on Scott O’Neill and his team in 2005.

Back then, the Eliminate Dengue Program was exploring a rather clever idea, which was to use Wolbachia bacteria to reduce the lifespan of Aedes aegypti mosquitoes.

The thinking was that if these mosquitoes died earlier, they would have less opportunity to spread dengue virus to people.

That idea alone was compelling enough to receive a Grand Challenges grant.

But what happened after that was even more interesting.

Eliminate Dengue scientists discovered, after much painstaking research, that the mosquitoes they had infected with Wolbachia were no longer able to transmit dengue virus.

They didn't need to kill the mosquitoes with Wolbachia at all – they just needed to introduce and establish the bacteria into wild populations of mosquitoes.

Until recently, this Wolbachia research has focused on reducing the incidence of dengue fever.

It turns out that this same species of mosquito also carries the Zika virus.

And as our understanding of the Zika crisis became more precise - in no small part due to proactive sharing of data from investigators in countries affected - it has become very clear that the Eliminate Dengue team and their collaborators likely hold the key to short-circuit the transmission of Zika.

Isn’t science great?

Discoveries like this are what Grand Challenges is all about.

But if you think about it, all this understanding was built on the back of science that you’d have a pretty hard time trying to justify investment for from Congress or Parliament.

The decision-makers would be, like, why are you working on this bug?

Bacteria that infect insects?


It has no meaning for my constituents with cancer, or heart disease, or diabetes.

And it takes time - remember I said 2005?

Time is a resource that’s in short supply these days.

One scientist describes the process of infecting the mosquito eggs with Wolbachia this way: “Imagine taking a knitting needle and poking it into a balloon. Then removing the needle without popping the balloon.”

I’m guessing that took a few tries.

But the fact is, that today, Wolbachia holds the key to overcoming a number of mosquito-borne diseases, including dengue, Zika, and chikungunya.

And the Ebola crisis and the spread of Zika remind all of us that we cannot wait for global crises to hit before making much-needed investments in basic science.

Now, I should say that I’m not arguing for a science-at-all-costs approach.

As much as I love science – and I do - those of us in the community can have a tendency to over-emphasize and potentially over-believe in the positives and forget that things can have a downside, or negative consequences.

So alongside championing basic science, I want also to encourage ethical science.

These are human beings and their lives we’re talking about.

That means being aware of unintended consequences.

And that, in turn, means taking an intervention like Wolbachia through a careful set of controlled and staged releases and doing so with a program of deep community engagement to assuage any anxieties or worries.

This is certainly true when the project is a research program, but it is no less true when responding to an emergency.

We must understand not only the short-term issues such as any specific health risks, but also in the longer term we need to seek to understand any environmental consequences.

Could you create a super mosquito that never dies - and it backfires?

Or what if we eradicate mosquitos?

We think the world will be better off without them but we don't know that, we just believe it.

Grand Challenges requires real world applications - transforming scientific research into a working public health intervention.

And as Eliminate Dengue has moved out of the lab and into affected communities, it has provided us with useful lessons about the value of R&D investment and the benefits of building strong relationships between scientists, researchers, community members, and philanthropists.

As the program is scaled across Australia, Indonesia, Vietnam, Brazil, and Colombia, there are plenty of lessons to learn - including the benefits of open source data and how that can help inform a precision approach to combating infectious diseases.

With that in mind, I’m particularly pleased to have the chance to talk in greater detail about the work of Eliminate Dengue in Colombia.

And for that, I’m joined now by Professor Scott O’Neill and Professor Jorge Osorio...

Thank you.


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