How does WHO track the variants of SARS-CoV-2, the virus
that causes COVID-19?
What are the challenges on the ground to tracking these variants, and how many
variants are we tracking at this time?
Hello and welcome to Science in 5.
I'm Vismita Gupta-Smith.
We are talking to Dr Maria Van Kerkhove today.
Welcome, Maria.
Let's start, Maria, with how does WHO track the variants of SARS-CoV-2?
It all starts with surveillance, making sure that we have really strong
surveillance and testing around the world so we know where the virus
is circulating.
We know where it is spreading most intensively.
And that testing needs to be supported by sequencing.
Sequencing has expanded dramatically over the last couple of years, and this really
helps us to track how the virus is changing.
It's natural for viruses to change.
The more the virus circulates, the more opportunities it has to change.
So strong surveillance, strong testing, including strong sequencing, helps WHO
with scientists around the world to look at those changes and determine which
of those changes is important and why.
So, Maria, since WHO is tracking the variants across the globe, tell us about
the challenges that countries face and WHO faces while tracking the variants.
So what is really difficult right now is as we are in the third year
of this pandemic, it's really important that we maintain and in fact, enhance
the surveillance systems that are on the ground.
Now, countries are facing many challenges, COVID-19, as well as
many other challenges that they have to deal with, other diseases.
And so keeping up with surveillance, keeping up with testing and making sure
that we have good tracking of this virus in at risk populations, people who are
over the age of 60, people with underlying conditions,
immunocompromised patients, to ensure that we are really understanding how
the virus is spreading,
where the virus is spreading is really critical.
And to maintain that on the ground in the third year is quite difficult.
But it is fundamental to the control strategy of COVID-19.
Not only do we need to improve vaccine access, as you hear us talk about
a lot, we also need to maintain public health services like surveillance and
testing and sequencing.
And this is critical for us to be able to determine how this virus is changing
and importantly, what that means for us in terms of our counter-measures,
looking at public health and social measures, looking at the use of
antivirals and looking at different therapeutics, as well as
ensuring that the COVID-19 vaccines remain effective.
And I just want to highlight that the COVID 19 vaccines remain incredibly
effective at preventing severe disease and death, including against the latest
variant of concern, Omicron.
So let's come now, Maria, to the variants that WHO is currently tracking.
WHO is working with surveillance officers,
public health officers, experts around the world to track this virus.
We work with our technical advisory group for virus evolution to assess each of the
variants and the mutations that are being detected.
There are five variants of concern that WHO has classified as variants of concern
at a global level.
The latest is Omicron and in fact, we are following several
sublineages of Omicron.
You've heard us talk about BA.1 And BA.2 There are other sublineages that are
circulating as well.
So we work with experts around the world to look at the characteristics of
the variants of concern.
Are they more transmissible.
And Omicron is more transmissible.
In fact, a BA.2, of the sublineages, is even more transmissible than B.A.1.
We're also looking at severity and looking at are these variants of concern
causing more or less severe disease?
Now, we do know that Omicron is less severe compared to Delta, the other
variant of concern that was circulating.
But Omicron has now replaced Delta worldwide and it is not more, BA.2 is not
more severe than BA.1, as I mentioned.
But we're also looking at antivirals, we're looking at vaccines.
And again, our vaccines remain incredibly effective at preventing severe disease
and death, including against both of the sublineages
of BA.1 and BA.2
Thank you, Maria.
That was Science in 5 today.
Until next time then.
Stay safe, stay healthy and stick with science.