Thread by @WillHayCardiff

A bit more information on the new variant of coronavirus in Wales.

[Thread]

There is ongoing surveillance of new variants of Covid all the time.

There are thousands that they are aware of.

Part of the reason why the situation has moved so quickly in Wales is that scientists have very recently become aware of how widespread this particular new mutation is in Wales.

Without getting too technical, basically, when a standard PCR test is done scientists have noticed a "drop out" of a particular gene.

It turned out that this drop out happens with the new variant.

So experts in Wales went back through some recent tests in Wales to see whether there was a drop out of this particular gene (the S gene).

It turned out that it was circulating in every part of Wales.

Because this variant spreads more effectively than the previous strain, experts think it could become the dominant one in Wales within a month because it is out competing the others.

This is why the guidance has changed so quickly.

The experts are now working to establish exactly how widespread it is.