In recent weeks, a handful of new coronavirus variants have emerged, sparking fears they may be more transmissible, lethal or evade immunity acquired by prior infection or vaccines.
Prime Minister Boris Johnson suggested there was early evidence that the UK, or Kent, variant may be more deadly, although government scientists stressed that the data so far is uncertain.
And in the latest development, further cases of the Brazilian and South African coronavirus variants were confirmed on Feb 9, as the Government announced tough new restrictions for arrivals into the UK.
Confirmed cases of the South African variant have risen from 100 to 119, according to Public Health England, with 51 probable cases. Six further cases of the Brazilian variant have also been confirmed, taking the total to 24.
It comes as a new coronavirus mutation first identified in Brazil was formally designated as a variant of concern by Public Health England, with 21 confirmed cases. Sixteen of the 21 confirmed cases of VOC-2021/02 were found in Bristol and the South West, with five other cases confirmed across England.
There have also been 42 cases of VUI-202101/02 identified, another new Brazilian variant. Both of the newly-confirmed variants have the E484K mutation which is found in the South African and existing Brazilian variants.
Public Health England has said the UK variant is now mutating to mimic the South African variant, with dozens of cases found across the country.
Genomic sequencing has identified a mutation of the spike protein, both in the original strain and the newer Kent variant of the virus, which is likely to render current vaccines less effective.
However, the deputy chief medical officer has urged people not to “panic” over the South African coronavirus variant, saying it is not likely to become the dominant strain in the near future.
Prof Jonathan Van Tam urged people not to delay if offered a vaccine, saying the UK virus type is “the clear and present danger”.
Vaccine Minister Nadhim Zahawi said on Feb 4 that there was a “library” of coronavirus mutations being stored to ensure the UK was ready to respond with updated vaccines.
There are already around 4,000 variants of coronavirus around the world, some of which are “more concerning than others”, said Mr Zahawi.