Recent tests show that there's already mutation in the Covid-19 strain identified as E484K, which was first detected in South Africa.
Calum Semple, who is part of a panel that advises the British government, told BBC radio that E484K was the "mutation of most concern", and had "occurred spontaneously" in the United Kingdom variant.
"While no assessments have yet been made on the effectiveness of the vaccines now in use in this country, it is entirely possible that their efficacy will be similarly diminished by this mutation".
A report from Public Health England (PHE) shows that sequencing has uncovered 11 Kent cases with the spontaneous E484K mutation from 214,159 samples tested.
The E484K mutation, which occurs on the spike protein of the virus, is the same change as has been seen in the South African and Brazilian variants that have caused global concern.
"The huge effort to test and trace and observe for reinfections and readmissions is incredibly important to help us understand what is going on here, but the honest answer is that we really just don't know about the clinical importance of this", Professor Sir Mark Walport, former chief scientific adviser to the government, told The Guardian.
As the door-to-door testing drive got underway, Public Health England also said scientists had discovered the same spike protein mutation in 11 cases involving another variant that is now the most prevalent form of the virus in England.
This potentially more concerning variant, which has been spotted since December 22 a year ago and spread to almost 40 countries including the United States, emerged independently of B.1.1.7 or the UK variant and shares some mutations with the same.
Sweden, which has spurned lockdowns throughout the pandemic, has seen the rate of new infections dip in recent weeks, though cases of the British COVID-19 variant have been increasing. However, Moderna's early results propose its vaccine is still efficient against variants that have this same mutation.
"Vaccines can be quickly adapted to cover new strains, but it still takes time until such modified vaccines will be available".
This mutation was also found in the new virus variant that emerged in the UK. The report added that the Liverpool area had identified about 32 cases of original coronavirus that also have a similar E484K mutation. However, the body's immune response may not be as strong.
"These are the behaviours that will protects us and each other from this virus".