WHAT’S THE DIFFERENCE . . .

. . . between virulence and transmissibility?

THE terms are often used interchangeably at the moment to talk about the emerging Covid variants, but they mean very different things.

We know that at least one of the new mutations of the virus makes it more transmissible – this means it’s easier to catch it and it spreads faster.

What has been seen is more outbreaks involving more people who turn out to have the new variant.

Virulence, however, refers to the ability of the virus to overcome the immune system and cause disease.

A more virulent virus would mean we’d be seeing more severely unwell patients, and as yet there is no evidence of this.