Watch Max Walsh's report on surge testing in Bristol
Eight libraries in Bristol and South Gloucestershire have been transformed overnight to accommodate surge testing for coronavirus, as NERVTAG classes the strain detected in Bristol a 'Variant of Concern'.
By lunchtime, Emersons Green's library had already handed out more than 400 tests to be completed at home and then returned.
It was confirmed last week that 11 cases of concern were found in Bristol, which prompted 'surge testing' to be made available in post codes where the virus is likely to spread.
Now 15 cases have been identified in the area and a further 6 cases elsewhere in England.
Matt Hancock told MPs earlier the number of people with the mutation is "small" and that the testing in Bristol and South Gloucestershire will ensure this is "under control".
How is the Bristol Covid mutation different from other strains?
Officially, it is called SARS-CoV-2 lineage B.1.1.7 with an additional E484K mutation.
This means it is a mutation of the variant that was first discovered in Kent in the autumn that is dominant in the UK at the moment, which is far more transmissible than the original version.
However it is the E484K mutation that scientists will be studying and concerned about the most.
It is the mutation that is in the co-called South African variant that ministers are trying to suppress elsewhere in the country.
The fear about this mutation is that it could make the current vaccines less effective, especially at preventing mild illness and transmission of the virus.
In a statement a spokesperson for NERVTAG said: "We have a high degree of confidence that the vaccines will work against variants, including B.1.1.7 and scientists on the group and in the wider industry have confidence that existing vaccines will prevent people becoming seriously unwell with the Bristol mutation.
"Work is now underway to adapt current vaccines to ensure they remain effective against all mutations."