ECDC on air.

The podcast of the European Center for Disease Prevention and Control.

Keeping up to date with European epidemiology.

Hello, my name is Nicholas and I'm your host for today's episode of ECDC on Air,

which is the podcast for the European Center for Disease Prevention and Control.

Today I have with me in the studio Eric Alm, who is ECDC on air, Eric. Welcome.

Thank you, Nicholas. It's really nice to be here.

So you're here to talk about virus variants and virus mutations. This is a topic which of course

has been very relevant during the COVID-19 pandemic. We've seen various different virus mutations,

for example, Omicron, becoming dominant and replacing other variants. Let me just start off asking

you a basic question. Why do viruses mutate?

Viruses don't really want to mutate. They mutate because of imperfections in their biological systems.

That's kind of the fundamental reason why they do that. And I mean, all of evolution is at its core,

kind of driven by these random mutations as they create the genetic diversity that then the natural selection can act upon and producing more fit organisms overall.

Okay, but it seems that the new variants that are becoming dominant, they're always more transmissible.

And that's the kind of the reason why they become

dominant, right? Is it always like that that they have a competitive advantage over the ones that

are less transmissible? Is it correct? Well, viruses that become dominant, they can do so by

random chance, but more likely is that they become dominant because they have some kind of competitive

advantage compared to other variants.

But what that advantage is can actually be different.

And at the beginning of the pandemic where basically the population was naive, so to say,

...