By ITV News Multimedia Producer Kavita Patel
A "new variant" or "new strain" of Covid-19 has been identified and it may be associated with the "exponential rise" of coronavirus in the south - particularly London.
But is this new strain more transmittable? What does this mean for the vaccine and should we be worried?
Virologist Dr Eleanor Gaunt, from the University of Edinburgh, and GP Dr Sarah Jarvis have told ITV News people should not worry about the new variant of coronavirus.
So what is this new Covid strain?
It's not uncommon or unusual to see multiple strains of the same virus, however this one is slightly different.
The variant, called "VUI – 202012/01", carries a set of mutations including an N501Y mutation to part of the genetic sequence which forms the spike protein.
Virologist Dr Gaunt said: "This new strain has a number of individual mutations most of which is seen before but not seen together.
"There was a mutation where a bit of protein has been deleted - we've seen that before, the virus strain has been deleted.
"But what is new, is the two new mutations are happening together."
Can the new strain make the illness worse?
No. There is no evidence the new strain can make the illness worse.
And GP Dr Sarah Jarvis told ITV News the strain could actually make the illness less severe.
Dr Jarvis said: "Overall, I don't think people should be unduly worried as on an individual level it does not seem that worrying.
"Viruses mutate all the time, that's why we have a different flu vaccine every year, so usually they do not cause more serious illness.
"If anything they tend to make the illness less severe, but what makes them successful as mutations is if they allow the virus to spread more rapidly."
When did this new Covid strain first appear in the UK? Dr Gaunt has said there is evidence which shows this strain was in the UK a few months ago.
She said: "The other thing we are seeing from analysis of this is that the first strain identified in UK was at the end of September but it's only just now being particularly noticed because of the rise of cases in the South of England and in London.
"It is not unusual to see this, new strains are happening and it can be a random event - a virus strain can be particularly dominate at any one point. But there is no evidence to suggest this virus strain is more transmittable."
Dr Gaunt added: "I genuinely don't think it's anything to worry about. The spread of this particular strain has coincided with the end of lockdown."
"The previous lockdown was not as effective as the full national lockdown in March - and it happened to be this strain."
How easy is it to tweak a Covid vaccine?
It's fairly simple to tweak a vaccine because it's done in a lab, Dr Gaunt has said. "In theory, it's very straightforward because it's straightforward to introduce a virus variant to a lab. Although in practise what you would do to switch vaccine productions might not be so straightforward but there is no indication that is needed right now," she said.
When asked whether the flu vaccine has to be changed each winter, Dr Gaunt said it does because "the flu vaccine comprises of four different types of flu".
"We often look at what happens in Australia from the summer before and how it reaches the Northern Hemisphere but in previous years the vaccine hasn't changed, but that is not always the case." Can the vaccine still protect me from this new Covid strain?
Yes. There is currently no evidence to suggest the vaccine cannot protect you from the new strain.
Dr Gaunt said: "The vaccine would work perfectly, the vaccine is not just targeting the protein, it's targeting other parts of the protein so this won't be too much of a problem."
"Everyone is really impressed with the roll out of the vaccine, if people can get the vaccine then they should," Dr Gaunt urged.
"It's an horrendous virus to catch, get the vaccine if you can."