Health officials are investigating a new Covid variant which has caused 49 cases of infection, mostly in Yorkshire and the Humber region.

Public Health England (PHE) has been monitoring the VUI-21MAY-01 variant since April. PHE said there was "currently no evidence that this variant causes more severe disease or renders the vaccines currently deployed any less effective". The agency said additional testing and tracing was being carried out.

The variant is one of a number "based on an unusual mutation profile", PHE said in an online update issued on Thursday. It added: "PHE is carrying out increased laboratory testing to better understand the impact of the mutations on the behaviour of the virus.

"All appropriate public health interventions are being undertaken, including additional contact tracing and targeted testing. Where cases have been identified, additional follow-up of cases, testing of contacts and targeted case finding will limit the spread of variants."

PHE said it would provide more information on the variant in a report later on Friday.

Dr Matthew Parker from the University of Sheffield is one of the scientists who first identified the variant. He said it was a mutation of the variant B11482 which was first spotted in other countries last year and it was not possible to say how it had arrived in Yorkshire.

A "variant under investigation" is one that acquires mutations that give it the potential to spread more easily, cause more severe disease or evade immunity from vaccines or previous infection. This new variant - one of eight under investigation - will now be monitored to see how it spreads and analysed in the laboratory. It would only be designated a "variant of concern" - like forms of the virus first detected in Kent, India and South Africa - if scientists conclude it does pose a heightened threat. The origin of this variant - also known as AV.1 - is unclear. There have also been cases detected in Greece and Chad.

New variants are a story that we will all become very familiar with in the years to come. Most will have little effect in the UK if the vaccination campaign continues to be a success. But it will be important to keep monitoring them in case one emerges that means the Covid vaccines need to be updated.

People suffering from this variation are easily identifiable: they go around wearing flat caps and sing "On Ilkley Moor Baht 'At"

Sorry, I'll get my coat.

Public Health England scientists have found the strain has 25 mutations, 10 of which are in the spike protein. As in the Indian variant, these natural alterations make the strain more infectious and render the vaccine less effective.

PHE has been monitoring the variant since April and has classed it one step below the Indian strain, which is a Variant of Concern. The number of cases has now doubled to 99, according to data from the Covid-19 Genomics UK Consortium.

Simon Clarke, an associate professor in cellular microbiology, University of Reading, said the mutations suggestions the variant had some kind of advantage, but the effects of most of them were currently "unknown".

People suffering from this variation are easily identifiable: they go around wearing flat caps and sing "On Ilkley Moor Baht 'At"

Sorry, I'll get my coat.

People suffering from this variation are easily identifiable: they go around wearing flat caps and sing "On Ilkley Moor Baht 'At"

Sorry, I'll get my coat.

@percy...
...ee bah gum I will get mine and follow you ....