Coronavirus explained: Why experts say more countries need to search for new Covid-19 mutations

Coronavirus explained: Why experts say more countries need to search for new Covid-19 mutations

In late November, scientists in the UK detected a troubling new Covid-19 variant.

Growth of the strain, which had been circulating at "very low levels" until two weeks previously, was on the turn.

And it was about to explode across the south-east.

The variant first came to light when experts were investigating why infection rates in Kent were not falling, despite severe restrictions in place to curb the spread of new cases.

Genetic sequencing of SARS-CoV-2 samples in the area discovered a cluster of the B117 strain, which came to be known as the Kent variant, spreading rapidly into London and Essex - and