Peter Hoejskov: The next pandemic is not a question of if
, but of when.
Alice Allan: Throughout history, pandemics have swept around the
world, leaving devastation in their wake.
What are we doing to prepare for the next one?
Hello, I'm your host, Alice Allen, and in this special
series of Health in Europe, I'll be going behind the scenes at
WHO and some of the European region's major public health
institutions to understand what the most likely causes of future
pandemics could be and what strategies are in place to avert
them.
I'll talk to the experts applying the lessons of previous
pandemics and focus in on the systems in place to spot threats
and reduce their impact.
I'll speak to the legion of public health experts quietly
working away, getting on with the not very glamorous but
incredibly important work of emergency preparedness Experts
in surveillance, genomic sequencing, epidemiology and
more the people who are containing outbreaks and laying
the groundwork to mitigate the effects of pandemics, not if,
but when they occur.
This is Health in Europe, and in this episode we explore H5N1
bird flu my name is peter sosa hoesko.
I work as a technical officer for food safety and zoonotic
diseases in the who regional office for europe, based in in
copenhagen zoonotic diseases have been around forever, but
while their threat has always been there, the virus behind the
Covid-19 pandemic, sars-cov-2, which originated in bats, and,
more recently, the jump of avian flu into cattle, has put them
back in the news.
Peter Hoejskov: So zoonotic diseases are diseases that can
jump from animals to humans.
So basically, a disease that originates in an animal and
transmits to a human, either directly, with direct contact
between animals and humans.
It can be domestic animals, it can be wild animals, or it can
be indirectly as well, through unsafe food, for example.
Alice Allan: Here in Europe we might think sometimes that, oh,
zoonotic diseases, that's something that happens somewhere
else in the world.
Why are zoonotic diseases also relevant in the European region?
Peter Hoejskov: Everywhere in the world, including in the
European region, there is close contacts between humans and
animals.
We have large agricultural productions in the European
region, livestock breeding sites , we have domestic animals.
We interact from now and then with wildlife.
So there is this constant interaction between humans and
animals.
We can't completely separate ourselves from the animal world.
So when we have this interaction there is also a risk
of transmission of diseases between animals and humans.
Alice Allan: Why are we hearing more recently about the threat
of zoonotic diseases?
Peter Hoejskov: We know that the SARS-CoV-2 virus this is the
virus that causes COVID-19 as a disease originated in the animal
population and then, through an intermediate host, ended up in
the human population and with the mutations that viruses can
have, then the transmission between humans can become more
serious, and that was exactly what we saw with the COVID-19
pandemic.
So I think that of course increases the interest and
triggers the attention of we need to be better prepared for
the next potential pandemic.
We don't know when it will happen, but we know it's very
likely to happen.
We also know that a lot of the new infectious diseases that we
see in humans originate in animals.
Alice Allan: Is there anything about our modern way of life
that is increasing the risk of zoonotic transmission?
Peter Hoejskov: Yes, with more urbanisation we get closer
interaction with the animal population.
We see climate change as a factor as well that affects how
the viruses survive and how they mutate.
We see changes in the agricultural practices, the way
we breed animals more intensive livestock breeding.
Alice Allan: Tell me about One Health.
Peter Hoejskov: One Health is an approach, it's a way of working
, seeing these health threats and the health challenges that
we are facing in a much more holistic and a more systematic
way, realising that we cannot prevent and prepare for
pandemics in the human health sector alone.
We need to also work across sectors, across disciplines.
We need to work with colleagues in other organizations or at
country level with other ministries.
So a very close collaboration, sharing of information, joint
risk assessments across the vituary services, agricultural
sector, environment sector and human health.
And that's exactly what One Health is all about.
It is to see health as one across these different domains
and encouraging closer interaction, closer coordination
and sharing of information so we can be better prepared and
act fast if we need to.
We have a formalized partnership with what we call the
Quartipartite Organizations, so that's the Food and agriculture
organization of the United Nations, it's the World
Organization for Animal Health, boha, and it's the United
Nations Environment Program, unep and then WHO.
So we work very closely together.
We have also developed joint guidance material for countries
on how they can operationalize the One Health approach
Basically, what are some of the tools, what are some of the
techniques and how can they better implement and work across
sectors at a country level, because One Health is not at the
global level, only of organizations working together.
It comes all the way down to communities and we know the next
pandemic is also going to start in a community somewhere, so we
need to be better prepared at community level.
So One Health is at all levels and across various sectors and
disciplines.
Alice Allan: Nicola Lewis is director of the Worldwide
Influenza Centre at the Francis Crick Institute in London.
It's a WHO collaborating centre and one of its key functions is
to track strains of influenza that are circulating among
animals and humans to understand how it's changing.
Nicola Lewis: So flu is fascinating and I think one of
the aspects of flu that is fascinating is it's continuously
evolving.
It's changing the whole time.
Is it's continuously evolving?
It's changing the whole time.
It's a virus that, when it replicates in a particular host,
makes mistakes, and it makes mistakes in its genome, and that
means that it's able to constantly evolve, and some of
this evolution means that it's able to escape prior immunity
that we might have to a particular flu virus.
So we're merely facing a challenge constantly to try and
keep up with this changing evolution.
Flu viruses are also fascinating because they can do something
else in terms of changing constantly.
They can undergo what we call reassortment, and this happens
when two different flu viruses infect a person or infect a pig
at the same time and they shuffle their genetic material
so that the progeny flu virus that comes out of the pig or
other human is actually different.
And this process of reassortment is also a way that
flu viruses evolve.
Now we know that flu viruses are particularly tricky to
understand from this point of view, because this whole
evolutionary process means that we have to stay abreast of this
evolution to understand where the next threat might come from.
Alice Allan: Big scientific advances have been made in the
last hundred years about understanding viruses and
tracking them.
How close are we to being able to keep up with flu?
Nicola Lewis: I think we're getting much, much better at
trying to keep up with the evolution of these pathogens.
I certainly think that new technologies are coming along
all the time and we make the most of those, particularly in
the influenza field.
But because flu changes constantly, it constantly
presents a new challenge to us.
So we certainly can't drop our guard with flu viruses, and I
think there is one certainty, and that is that there will be
another flu pandemic in the future.
Alice Allan: Can you think of a particular moment when flu has
done something that has shocked or surprised you?
One of those moments when you've gone gosh wow, flu.
That was interesting.
Nicola Lewis: I think one of the major surprises has been quite
recently, actually with the H5 highly pathogenic viruses that
have been circulating in bird populations, and we've been
facing a massive challenge with these viruses since about 1997.
But in about mid-2020, we suddenly saw a radical shift in
the way that these viruses were evolving.
All of a sudden, rather than being confined to particular
geographic regions, they managed to switch back into wild birds,
they managed to infect many more wild bird hosts and then
they managed to spread globally to the extent that since 2020,
they've spread not just throughout Eurasia, not just
through into Europe, into Africa , but they've also hopped over
the Atlantic and have now spread right the way down North
America, south America, and have just turned up in Antarctica.
We have never seen this kind of situation with a highly
pathogenic H5 virus before, and I certainly think that if you'd
asked me in 2019, this would not have been the picture I would
have conjured up in my mind about what bird flu could do.
Alice Allan: How are scientists responding to this new behaviour
?
Nicola Lewis: As researchers, we are very committed to
understanding what has changed with the virus, but also what we
can do to help populations of animals, and indeed the human
population, be prepared to be able to counteract these
infections, to be able to mitigate them and to essentially
prepare for a potential pandemic from these viruses.
So there are a number of different initiatives that we
undertake to keep up with these viruses.
The first is to sample these viruses in animal populations to
characterise them, to sequence them, to antigenically
characterise them, to understand what they look like in these
animal populations, in bird populations, but also when
they've spilled over into terrestrial mammal populations
around the world.
And the next part of this is to understand what these viruses
look like relative to what we call candidate vaccine viruses.
And these are viruses that the WHO network, the Global
Influenza Surveillance Response Network, worldwide we take these
viruses and we try to understand the similarity to
potential candidate vaccine viruses we might have to use
were there to be a human pandemic.
And so, twice a year, the WHO collaborating centres that are
part of this GIST-Risk Global Influenza Surveillance and
Response Network come together twice a year and we have a very
important job to do twice a year .
One is to make recommendation for seasonal influenza viruses
and for the vaccine strains, but the other is to look at the
viruses that are circulating in animal populations and to think
about what we need to prepare for, what kind of candidate
vaccine viruses we might need to have in our armoury to help us,
were there to be a pandemic tomorrow in our armoury to help
us, were there to be a pandemic tomorrow In the European region.
Alice Allan: detections of H5N1 have been made in farmed fur
animals in Finland and Spain, and also in domestic cats in
Poland.
Aisling Vaughan is an epidemiologist who works for WHO
Europe in the High Threat Pathogens team.
I started by asking her what the team had learned from
working on these outbreaks.
Aisling Vaughn: I think what we learned from these events in
Europe most recently was that a strong foundation of trust
amongst stakeholders is really really important.
It enables rapid information exchange, it allows for
coordinated multi-sectoral efforts and it really drives
decisive actions to effectively prevent any further viral spread
and then, of course, safeguard both human and animal health.
Alice Allan: How do you assess the current risk of H5N1 to
humans, particularly in the light of the recent detections
in cattle in the US?
Aisling Vaughn: So it's important to remember that this
virus mostly affects wild birds and domestic birds.
It rarely affects humans and there's really no evidence yet
that this virus has acquired the ability to spread well from
person to person.
And despite the high number of clade 2344B outbreaks we've seen
, and the detections in animals and as well the human exposures
to this virus at the human-animal interface,
relatively few infections have actually been reported to date,
which is reassuring.
So, overall, since the beginning of 2021, 28 detections
of H5N1 in humans have been reported to WHO, including the
most recent case who had exposure to dairy cattle.
So, of all of the H5N1 cases reported in Europe and North
America, they have been asymptomatic or mild.
So, for example, the most recent case in the US reported
conjunctivitis as their only symptom.
All H5N1 cases so far have been sporadic infections.
They've occurred through direct or indirect contact with
infected birds or infected mammals or environments such as
live poultry markets or other premises with infected animals,
and among these cases, there have been no reported human to
human transmission and, in fact, there have been no reported
human human transmission of H5N1 since 2007.
So, based on everything we know , based on all the information
available, who assesses the current overall public health
risk posed by H5N1 to be low, and for those with exposure to
infected birds or animals or contaminated environments, the
risk of infection is considered low to moderate.
But these viruses are continually evolving and
spreading in birds and animals, so continuous real-time
monitoring is needed.
Maria van Kerkhove: I think with almost certainty we will have
another flu pandemic in our lifetime.
Alice Allan: Dr Maria Van Kerkhoff is the Acting Interim
Director of the WHO's Department of Epidemic and Pandemic
Preparedness and Prevention.
She also leads on COVID-19 emergency management and she's
technical lead of the WHO Health Emergencies Programme.
She started her career working on avian influenza 20 years ago.
Maria van Kerkhove: I became interested in viruses, pathogens
, when I was in college and when I was doing my PhD at London
School of Hygiene and Tropical Medicine.
And as part of my PhD work I was based in Cambodia and I was
working with Institute Pasteur Cambodia on H5N1, on avian
influenza, and at the time there were six or seven human cases
in Cambodia.
So it was relatively new and what we were doing there with
colleagues across the Ministry of Health, the Ministry of
Agriculture, institute Pasteur, where we're doing these outbreak
investigations, and I was fascinated with outbreak
investigation it was multidisciplinary, it was all
One Health before it was even called One Health, you know and
it was really just early detection and early action to
prevent onward spread.
So we were doing all these complex, comprehensive
investigations in the field.
Oh my gosh, I absolutely loved it.
Alice Allan: Why are we hearing so much about H5N1 recently?
Maria van Kerkhove: So there's a lot of attention right now to
avian influenza and there's a massive epizootic across the
world.
It has expanded greatly in the last couple of years.
This is particular on H5N1, but not only H5N1.
We see in wild birds, we see in domestic poultry, we see in
spillover into mammals, including humans.
But this is being detected in new countries Right now.
There's been quite a lot of attention on H5N1 in dairy cows,
in dairy cattle in the US, and you know it is unfortunate that
the world starts to pay attention when you see this in
high-income countries.
But we will use this attention to draw awareness to one the
global influenza and surveillance response system
that's been in place for 70 years.
Who did not wake up to flu.
We've been working on this for quite a long time because we
know there's seasonal influenza, there's a potential for
pandemic influenza and there's all these novel subtypes of
avian influenza.
And we work with the PIP framework of looking at how do
we have better capacities in countries for these types of
detection, but also how do we share viruses with our global
lab network, our national influenza centres, our WHO
collaborating centres to identify certain viruses that
should be thought of for vaccines.
Alice Allan: The PIP framework is WHO's Pandemic Influenza
Preparedness Framework.
Maria van Kerkhove: So we have these candidate vaccine viruses,
including many H5N1 vaccines, which prompt us already to have
H5N1 vaccines, which prompt us already to have H5N1 vaccines in
development.
Now I do want to contextualize this that since 2017, we've only
had 28 human cases of avian influenza and we have not seen
human-to-human transmission.
We're constantly looking because our worry is that these
viruses can be more adapted for transmission.
We have not seen that yet, but we are concerned.
The more opportunity this virus has to circulate, the more
opportunities we see for infection in different species,
and these viruses can combine the genetic components of it,
can combine and potentially cause a new virus of influenza
that could be highly transmissible.
That's what happened in 2009.
So we're constantly thinking about this.
Not just thinking, but taking action to be better prepared.
What we want to do is prevent, prevent, prevent.
There are some treatments for influenza.
We have vaccination, so there's a seasonal vaccine campaign
every year.
We urge people to get not only COVID vaccines but also
influenza vaccines, and there are H5N1 vaccines in development
, should we need them.
Alice Allan: This recent species jump into cattle.
What's WHO or what are your partner agencies doing to
understand that development and any potential risks to humans?
Maria van Kerkhove: Yeah, quite a bit actually.
So what we're trying to do is enhance the surveillance.
We have a global surveillance system in humans as part of our
GISRIS system, which is looking at sentinel sites, so patients
that are going into hospitals.
Some are non-hospital sites.
We're working with FAO and WOHA on surveillance in animals, so
in wild birds, in poultry, in livestock, and now that we're
seeing infections in certain species we want to make sure
that those species are tested more systematically.
So not just dairy cattle in the US, but we would ask more
globally for surveillance to include these animals, but not
only in the animals themselves but looking in the products of
those animals, like milk and milk products.
So there's a lot of work that has to happen there to
understand the extent of circulation.
We advise that sequencing be conducted and shared because
there's a lot that we can gain in our understanding of
transmission and circulation with the sequence information.
So I don't have the full picture, but that's just because
the work is ongoing as we are talking about this right now.
We also are very actively engaging with our WHO
collaborating centers, national influenza centers, to make sure
that samples that need to be in the right labs to do the right
types of laboratory research type studies are ongoing and
that information is shared and we're constantly doing risk
assessments.
Alice Allan: What kind of key factors could contribute to a
species jump to humans for H5N1?
Maria van Kerkhove: So one is opportunity right.
So, as these species intermix with each other, you know, we
have wild birds that are flying, and so there's opportunities
for the virus to spread between poultry and other species, wild
birds and other species and that's what we think has
happened here, based on the sequencing information.
We're also very carefully looking at the viruses and
looking at the mutations within the viruses and any changes that
would favor mammalian adaptations what they call it
would favor a transmission in mammals.
Now we're seeing some changes, but these are mainly, primarily
poultry viruses and they have not adapted well to transmit
between people and in mammals, and that's a really important
thing that we're tracking.
We have a lot of really fantastic I mean this with the
utmost respect super nerdy scientists, who I adore, around
the world who are looking at this with us.
So it's not just WHO sitting here saying what do we think?
What we do is we bring together the best minds in the world as
part of our global influenza surveillance and response system
.
We do this for COVID as well and for SARS-CoV-2, of what do
these changes in the viruses mean from a public health point
of view?
So that is something that's also ongoing.
Alice Allan: There've been a lot of headlines recently
predicting that the next pandemic is going to be caused
by an influenza virus that's jumped from animals to humans.
How do you assess that risk?
Maria van Kerkhove: For me, flu is a certainty because it's so
much in circulation.
It's infected many different species.
We have avian influenza and the opportunities for reassortance,
the opportunities for a pandemic influenza virus are
high.
That's why we have a whole system in place to be prepared
for this.
The challenge is will we see another coronavirus pandemic,
given that we had SARS-CoV-2 cause, a pandemic for sure.
This is an opportunity.
Question is will we see an arbovirus pandemic?
Now, I'm not saying this to scare people who are listening
to this, but for us it's something that we have to be
prepared for.
So we have to think out of the box, really prepare for what are
the known threats, but also think out of the box, for you
know, really prepare for what are the known threats, but also
think out of the box, you know, for something different, perhaps
waterborne or whatnot.
So for me, pandemics, unfortunately, are part of what
we will deal with in our lifetimes.
I don't believe this will be the last pandemic we will deal
with in our lifetimes.
Alice Allan: We know we weren't prepared for the COVID-19
pandemic.
Are we prepared for the next one?
Maria van Kerkhove: Yes and no.
Yes because we do have strong systems that are in place.
We have learned a lot in the last four years from COVID.
We have strengthened PCR capacity, sequencing capacity.
We have stronger community engagement.
We have many systems that are in place to ensure better
clinical care and infection prevention and control and good
coordination in our emergency operation centers and supply
chain.
No, on the other hand no because I think the world's
trust in science you know there's been a lot of, there's
been a lot of distrust, um, over the last couple of years, and
that's something we have to work on.
You can develop the best interventions in the world, but
if they're not implemented by communities, they're useless.
We still have challenges with equity and access to these
materials and I think you know, in many respects we are better
off and in others we are not.
I'm optimistic.
That's what gets me out of bed every day, otherwise I wouldn't
be able to do this job.
I'm hopeful with the pandemic agreement that is being
discussed and negotiated right now by all of our member states
to get this done.
They want to get this done because we have to do.
We can't just have a handshake and say, oh, we'll do better
next time.
There have to be commitments in place to ensure that we do
better the next time.
Again, covid-19 did not have to be as bad as it was, as it is,
and we owe it to our children, our grandchildren, to make sure
that we we keep up these systems and have that commitment in
place to make sure that we do better the next time.
Alice Allan: In future episodes I'll talk to experts who are
tracking disease outbreaks, trying to understand them better
and preparing for future pandemics Not if, but when they
happen.
Health in Europe is produced by the World Health Organization.
Music for this episode is by Ben Howells, Richard Duttonall
and Gareth Thomas.
Sound engineering is by David Barrett.
My name's Alice Allen.
Thanks for listening, Thank you .