As vaccines are rolled out around the world, one of the questions being asked is whether they will work against the new and more infectious coronavirus variants that have been emerging. There's the UK Covid variant, the South African variant, the Brazilian variant and scientists in Los Angeles have found what they believe to be a Californian variant.
Viruses are constantly evolving and mutating and scientists track the changes through genome sequencing. Britain is a world leader in doing this. Newshour's Julian Marshall has been speaking to Sharon Peacock, executive director and chair of the Covid-19 Genomics UK Consortium. How do scientists first become aware of a new mutation?