Door-to-door coronavirus testing has begun in parts of England, after cases of the South African variant of Covid-19 were found unexpectedly.

Two cases of the variant were discovered in Surrey, and urgent testing is also taking place in London, Kent, Hertfordshire and Walsall, in the West Midlands.

So far, 105 cases of the strain have been identified to date across the UK, but this is the first signal of wider community spread.

There is currently no evidence that the variant causes more severe illness.

The infected individuals had no known links to travel or previous cases, and were identified after random checks on tests by Public Health England.

The surge testing programme is carried out to test as much of a local population as possible to trace and then contain an outbreak. 

Ruth Hutchinson, director of public health for Surrey, where one surge testing programme is underway said: “This is a precautionary measure – the more cases of the variant we find, the better chance we have at stopping it from spreading further.

“By playing your part and taking the test, you’ll be helping to keep your community and your loved ones safe.

“It’s really important to say that there is currently no evidence that this variant causes more severe illness, so you don’t need to worry.”

What is the South African variant?

The South African variant is officially known as 501.V2. It is one of a few Covid-19 variants that have caught the attention of experts, after they caused an alarming increase in infections.

There is no evidence that the new variant causes much more serious illness for the vast majority of people who become infected. There are, however, concerns that it can spread more quickly, and that existing vaccines may not be quite as effective against it.

The variant carries a mutation of Covid-19 called E484K, among others. The mutation differs from the UK mutation found in Kent late last year. Both mutations were found to be more contagious.

While the UK variant is unlikely to harm the effectiveness of the Covid-19 vaccine, scientists have said there is a chance that the South African variant may alter the effectiveness to some extent.

A preliminary study testing the Pfizer Covid vaccine against one of the mutations found in the South African variant appeared to show the jab is effective against the mutated virus.

Early results from Moderna suggest that its vaccine is also still effective against the South African variant, however immune response may not be as strong or prolonged.

Vaccines can be redesigned and tweaked in a matter of weeks if necessary to tackle new variants.