Greetings from the World Health Organization.
Over the past 15 years,
malaria death rates have plunged.
The progress made between around 2000
and around 2015
in the fight against malaria was monumental.
Access to malaria prevention and treatment
was greatly increased, and malaria cases and death
were cut by about half.
And all of this was in large part the result
of a massive global investment in wiping out malaria.
When things were scaled up like bed nets, vector control,
initially you could see that
we were bringing the burden down.
What is scary is for the last sort of seven years,
we're not making progress.
We got to the point where we are no longer able to drop
the death toll below this threshold that we've reached.
That clearly indicated
that we have done a really fantastic job,
but that to some extent, the tools that we have in hands
basically have reached the fundamental protective limit.
The obvious question is what do we do now?
Mosquitoes are resilient organisms.
They're adapting to be resistant
to traditional vector-control methods.
Similarly, the parasite itself is adapting
to be resistant to antimalarial drugs.
Researchers continue to improve upon current
strategies that have shown great efficacy in the past.
This includes finding new compounds for insecticide-treated
bed nets and developing new antimalarial drugs.
A lot of people are trying to come up with new tools
that can be implemented additionally or as an alternative
to current strategies that we have.
Some of the most exciting new developments
are in the area of modified mosquitoes,
vaccines, and monoclonal antibodies.
But in order to understand the new tools, how they work,
and why they're needed,
you first have to really understand
what we're up against.
Malaria is a very ancient disease
that has been with us since really our very beginning.
There are more than 3,000
different species of mosquitoes,
and the only mosquitoes that carry the malaria parasite
belong to a single genus called anopheles.
The most severe form of malaria is caused by the parasite
Plasmodium falciparum.
If malaria is detected
and treated within the first 48 hours of symptoms,
most cases of the illness are mild and easily resolved.
However, if it's not diagnosed and treated quickly,
the parasite count can grow rapidly,
leading to coma and even death.
I trained as a pediatrician.
In the district hospital I was in, the wards just filled up with malaria.
I could admit to the high-dependency unit,
five kids in a night. In one night.
I grew up in a village, and I don't know even
any single person in Burkina Faso
who have not experienced malaria.
And this is the same thing all over West Africa.
In 2020,
29 countries accounted for 96% of the world's malaria cases.
All of those countries are in sub-Saharan Africa.
Four of those countries accounted for
over half of all malaria deaths.
It's a whole chunk of humanity
that's severely held back by a treatable disease.
So we should, we should just solve it. You know.
The malaria parasite lifecycle is quite complex.
You get from the mosquito into the human host,
passing through the liver,
then through the red blood cells
in the bloodstream, and then back into the mosquito.
So in order to control malaria,
you have to break the cycle somewhere.
The question is where and how.
One strategy that has been used for years
is to stop the cycle by controlling the vector,
the mosquitoes.
This comes down to three main strategies.
Keep the mosquitoes from biting people,
reduce or eliminate the mosquito population
that is transmitting malaria,
or manipulate the mosquito
so that it is not an effective host for the parasite.
Probably the most popular strategy at the moment
that is still in the lab,
but has potential to be utilized in the field,
is the genetic control of mosquito populations.
And these genetic traits can be of two different kinds.
One is called population replacement, where you replace
a population that is capable of transmitting malaria
with a population that is incapable of doing so.
And one is called population suppression,
because you actually induce sterility
in those mosquitoes,
and by the end
you reduce the number of mosquitoes
that can transmit the disease.
One of the paradigm shifts
that we are working on is gene drive.
If you take the conventional foundation of genetics,
any specific gene of interest has a 50/50 chance
of being transmitted to the next generation.
In a wild population,
the trait of interest will quickly disappear
in the sea of mosquitoes
that have not been genetically modified.
Gene drive makes it possible to get around this mechanism.
It gives the gene of interest 70, 80, or even 100%
chance of being transmitted to the next generation.
There's a lot of excitement
around the potential for this approach.
It could be a game changer.
There are also concerns around
modifying or eliminating a species.
These are questions that both researchers doing the work,
and communities where the intervention would be deployed,
are grappling with.
So what will happen maybe in 10 or 15 or 20 years?
What if something is going wrong?
That's a really very valid question,
but every year you have about 600,000 people
dying from malaria.
Something is already wrong.
People really want to understand
what risk is it for us
and what is the benefit that's going to add to our life?
It's extremely important to build trust.
How can I make sure that whenever, you know,
this technology is ready,
it's going to solve more my problem than, you know,
bringing more problem to me.
What if there was a way
to change the mosquito without genetic modification?
Scientists have discovered a way
to do that for a different species of mosquito.
Aedes aegypti, the mosquito that carries viruses
such as dengue, yellow fever, Zika, and chikungunya.
They modify this mosquito's ability
to host and transmit these viruses
by introducing a naturally occurring bacteria
called wolbachia.
Wolbachia is this really interesting
intracellular bacteria of insects.
Up to 50% of all insect species
have wolbachia naturally.
But there's a number that don't,
including a range of mosquitoes.
When you introduce the wolbachia bacteria
to the Aedes aegypti mosquito,
it makes it harder for viruses
to replicate inside the mosquito.
It also has a mechanism that mimics gene drive,
pushing the virus-limiting trait
through to future generations.
It's a natural gene drive that also prevents
transmission of pathogens from the mosquito to humans.
You know, who would have thought?
Obviously, there's been a lot of interest in trying to transfer
this sort of technology to the mosquitoes
that transmit malaria.
Wolbachia bacteria are not so good at colonizing
anopheles mosquitoes for reasons that are still unknown
and that we are trying to understand.
Until recently, there's been little incentive in studying
mosquito biology.
If you can kill mosquitoes, why should you study them?
However, it's becoming more and more apparent
that it's only by understanding better
how parasites are transmitted
that we can also come up with interesting and novel ideas
that can help tackle malaria transmission.
Controlling mosquitoes is just one possible point of attack.
There's also the option
of attacking the parasite
once it's inside the human host.
In the late 1960s,
scientists began searching for a malaria vaccine.
But it's much harder
to develop a vaccine for a parasite than a virus.
You're chasing a complicated and evolving
target and so the scale of the challenge is much harder.
In 2021, the WHO approved the first-ever malaria vaccine,
and it was groundbreaking.
What we're witnessing today is the deployment,
for the first time in history of a malaria vaccine,
which happens to also be a first vaccine
against the human malaria parasite.
While the first formulation of the vaccine
is only about 30% effective,
scientists are using this foundation
to find new ways to improve upon its efficacy.
Including combining the vaccine with preventive drugs,
administering the vaccine seasonally to increase
immune responses during the rainy months
when transmission rates are higher,
and creating multistage vaccines
that target different stages of infection.
Technologies have moved
very rapidly, so there's a lot of good work
trying to find malaria vaccine candidates.
Researchers are optimistic that continued
focus on these strategies could create a vaccine
with a much stronger defense.
The advances in vaccine research have also provided a foundation
for developing another tool for malaria prevention,
monoclonal antibodies.
Similar to vaccines, monoclonal antibodies provide the body
a boosted defense against disease,
but they are different in one key way.
Rather than train the immune system
to defend against future infections,
monoclonal antibodies are an injection of
ready-to-fight molecules.
Monoclonal, I think, has a lot of potential.
So, these are laboratory-made antibodies,
so they take antibodies from patients,
they clone it. It's a single clone. This is why 'monoclonal.'
And then they're producing large quantities
and then you give an injection.
The results that have been published are very promising.
The challenge is can we make it affordable
in low-to-middle-income countries,
and the scale we're talking about.
It's still early days.
It's very exciting, but I think we still need to be
a little bit cautious.
As researchers work on improving the vaccine
and explore approaches for monoclonal antibodies,
progress continues in developing new antimalarial drugs.
The goal is to create drugs that are simple to take
and inexpensive to produce and administer on a large scale,
and to stay one step ahead of the constant challenge
of drug resistance.
Many of the new developments in vector control, vaccines,
and drug therapies are years away
from being implemented in the field.
And that reality is particularly troubling
when you look at the potential
for the implementation of new tools to be outpaced
by the spread of drug resistance.
I'm physically based on the Thai–Myanmar border.
We are the sort of the epicenter
of drug-resistant malaria.
If you trace the history of the fight against malaria,
the race against drug resistance
leads back to this small corner of the world
time and time again.
When chloroquine resistance
emerged in Southeast Asia and spread to Africa,
that resulted in, in the 1990s,
in millions of deaths, millions.
Recently, the history is also repeating itself.
We start to see the malaria parasites
which are resistant to
artemisinin combination therapy or the ACT.
ACTs, artemisinin-based combination therapies,
are widely thought to be the best
malaria drug therapies we've ever had.
If we lose the drugs,
we will not be able to control malaria.
And there are new drugs on the horizon,
but at least 3 to 5 years before the new drugs arrive.
The bottom line is that it's much better
to eliminate malaria than to control it.
In order to eliminate malaria here,
a consortium of organizations is working in communities
to diagnose and treat as many people as possible.
Early diagnosis and quick treatment can be lifesaving,
not only for the recipient,
but for their community as well.
If you manage to treat the people
within the first 48 hours of their fever,
they don't transmit malaria.
Now we see that falciparum is on the rise again.
We are trying our best
to keep this kind of logistic chain and
keep our malaria post and malaria program alive.
Malaria's a disease of the most remote, difficult to access places.
You know, the further away you go from health structures
the more malaria.
If you have war such as in Myanmar,
it comes back. Bang.
I think what people need to understand,
is that it's far from over.
We must throw everything that we can at trying
to defeat malaria.
We're all looking for that holy grail,
and maybe one day we will get there.
But I think that right now it's proving to us
that we need several tools
and we need to keep having innovative tools.
So we keep looking for something that is better.