The coronavirus mutation in Bristol is thought to be more transmissible than the original virus form, says Bristol City Council.
Health Secretary Matt Hancock spoke yesterday (February 2) in the House of Commons about "cases of mutations of concern" in Bristol and Liverpool.
Tests showed a mutation called E484K in the Bristol and Liverpool cases.
Although the mutation in Bristol is a form of the Kent strain, the E484K is also a feature of the South African variant.
In a briefing today (February 3), Bristol's public health director Christina Gray said the mutation in Bristol is not thought to be more transmissible than the Kent variant, but it is more transmissible than the original form of the virus.
She added it is associated with the South African strain but "not the same thing".
There are at least 11 cases of the mutation in Bristol and 32 in Liverpool. Ms Gray said the 11 local cases were picked up as part of the national surveillance system.
All positive cases in the city are being sampled to check for the presence of the mutation.
Ms Gray added Bristol does not have a "tight cluster" of mutated Covid cases but they are spread across different parts of the city.
She said it wasn't appropriate for her to say where those were, despite the Government having released the postcodes where South African variant cases have been found.
Dr Susan Hopkins from Public Health England has said existing vaccines may offer less protection against the South African variant, though they should still offer a good level of immunity.
You can follow the latest updates from the briefing here.
