It was announced last week that the new Covid variant of concern, Omicron, has arrived in the UK – so what symptoms should people be looking out for?

There has been no official information on any differing symptoms with this new strain of Covid so NHS advice remains to look out for a high temperature, a new, continuous cough or a loss or change to your sense of smell or taste.

However, the South African doctor who raised the alarm about the Omicron variant told The Telegraph the symptoms are unusual but mild.

Dr Angelique Coetze said: "Their symptoms were so different and so mild from those I had treated before.”

She saw both children and adults with intense fatigue, saying it was mostly healthy men who turned up “feeling so tired”.

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Chris Whitty: Global spread of Omicron “inevitable”

England’s chief medical officer Professor, Chris Whitty, has said while it is clear Omicron is highly transmissible, it is not yet clear how effective the vaccine will be as protection against it – but said those who are vaccinated or receive the booster jab will be less likely to become seriously ill.

The UK may need to “face up” to the possibility of further action if the Omicron variant is very transmissible, the UK’s chief scientific adviser has said.

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Why is Omicron of concern?

Scientists have said they are concerned about the B.1.1.529 variant as it has around 30 different mutations – which is double the number present in the Delta variant.

The mutations contain features seen in all of the other variants but also traits that have not been seen before.

Dr Susan Hopkins, chief medical adviser of the UK Health Security Agency (UKHSA), told BBC Radio 4’s Today Programme: “If we look at those mutations, there’s mutations that increase infectivity, mutations that evade the immune response both from vaccines and from natural immunity, mutations that cause increased transmissibility.

“It’s a highly complex mutation, there’s also new ones that we have never seen before.”

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Will vaccines protect people against Omicron?

It is too early to say. Work is under way to see whether the new variant may be causing new infection in people who have already had coronavirus or a vaccine, or whether waning immunity may be playing a role.

Professor James Naismith, director of the Rosalind Franklin Institute in Oxford, has said the new variant will “almost certainly” make vaccines less effective, though they would still offer protection.

Pfizer/BioNTech, which has produced a vaccine against Covid-19, is already studying the new variant’s ability to evade vaccines.

Experts have said vaccines can be tweaked to tackle new variants as they emerge.

Mr Javid said: “We know this is new out there. We don’t know enough about it yet. But for what we do know, we know that the protections that we have, especially the vaccines, are hugely important.”