There are now multiple mutant strains of Covid being monitored by Public Health England as some may spread faster, be more deadly or be immune to vaccines.
Public Health England (PHE) is investigating strains of coronavirus in the UK which have developed mutations. Eleven cases in the Bristol area have been identified as the highly contagious variant that originally arose in Kent but are now showing the E484K mutation.
A cluster of 32 cases in Liverpool also have the same mutation but relate to the original strain of coronavirus that has been around since the start of the pandemic.
The South African variant - which also shows the mutation - is under investigation in at least eight postcode areas of England where cases not linked to travel