Mu Covid Variant: Should We Be Worried In The UK?

Mu has been designated a 'variant of interest' by the World Health Organisation.

Another variant of Covid-19 called the ‘Mu’ variant is being watched carefully by health officials. As of last Friday, there were 2,000 cases of the Mu variant in the US, according to the Global Initiative on Sharing All Influenza Data.

The US’s leading infectious disease expert, Dr Anthony Fauci, said though there are cases of the Mu variant in the US, it’s not the dominant variant.

Dr Fauci told the White House Covid response news briefing: “We’re keeping a very close eye on it. It is really seen here, but it is not at all even close to being dominant.”

He added: “We’re paying attention to it, we take everything like that seriously, but we don’t consider it an immediate threat right now.”

Last week, the World Health Organisation designated Mu as a “variant of interest,” adding that it can potentially evade immunity granted from a previous Covid-19 infection or the vaccine. There have also been cases of Mu in the UK, so here’s what you need to know.

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What is the Mu variant?

So far we know that Mu has changes, called mutations, which may mean it’s able to evade some of the protection we get from Covid vaccines.

The evidence is still emerging, but early data suggests it might resist our defences in a similar way to the Beta variant – the variant of concern that first originated in South Africa.

The four other variants of interest are Eta, Lota, Kappa and Lambda. These variants are essentially on a watch-list – they’re not as prevalent as “variants of concern”.

Where did the Mu variant originate from?

It was first discovered in Columbia in January. A Columbian health official said the variant was responsible for the third Covid surge that occurred there from April to June.

The WHO said: “Although the global prevalence of the Mu variant among sequenced cases has declined and is currently below 0.1%, the prevalence in Colombia (39%) and Ecuador (13%) has consistently increased.”

It has also been spotted in South Korea, officials announced on Friday, with three infections in people who have traveled from Mexico, the US, and Columbia.

How many cases are in the UK?

So far, there are at least 23 cases of Mu in the UK. A report by Public Health England (PHE) in July said most were found in London and among people in their 20s. Some of those testing positive for Mu had received either a first or second jab of the Covid vaccine.

Should we be worried?

The WHO added Mu to its watchlist on August 30 after it had been found in 39 countries and was found to possibly cluster some mutations that may make it less susceptible to the immune protection many have acquired.

However, though the variant has been around since January, it hasn’t overtaken the Delta variant, which is the dominant variant across most of the world.

The US Centres for Diseases Control and Prevention has yet to call Mu a variant of concern. As of right now, there are four variants of concern on the organisation’s list: Alpha, Beta, Gamma, and Delta. The Mu variant has also not been designated a variant of concern in the UK.