Now WHO warns of threat of ‘Mu’ variant found in Colombia – and it’s already been found in Britain
- World Health Organization named the variant ‘Mu’ after it was dubbed B.1.621
- It was first found in Colombia in January but has now spread to other countries
- Almost 50 cases have been recorded in Britain, and hundreds in the US
World Health Organization bosses are now officially tracking another Covid variant named ‘Mu’.
The mutant strain — which also has the scientific name B.1.621 — was first detected in Colombia in January.
Almost 4,000 cases have been spotted since then in more than 40 countries, but its prevalence started to drop in August amid the spread of the Delta variant.
There have been almost 50 cases detected in Britain so far, and it has been identified hundreds of times in the US.
The WHO’s weekly bulletin said its mutations suggest it may be more resistant to vaccines, as was the case with the South African ‘Beta’ variant.
It also has the N501Y mutation which could make it more infectious. This was blamed for the rapid spread of the Kent ‘Alpha’ variant.
But the agency warned more studies would be needed to examine this further, with Mu now formally labelled a ‘variant of interest’.
Almost 4,000 cases of the variant have been detected to date since it first emerged in January, but the number of infections has fallen in recent weeks with the emergence of the Delta variant. This graph shows the seven-day average proportion of cases that were due to the Mu variant worldwide. They reveal its prevalence has fallen recently
Almost 50 cases have been spotted in Britain to date. But these have remained low overall amid the spread of the Delta variant. The above graph shows the B.1.621 variant as a proportion of all cases detected in the UK by date
The variant was first spotted in Colombia in January. It has since been detected in 40 countries
The WHO report said: ‘Since its first identification in Colombia in January 2021, there have been a few sporadic reports of cases of the Mu variant and some larger outbreaks have been reported from other countries in South America and in Europe.
‘Although the global prevalence of the Mu variant among sequenced cases has declined and is currently below 0.1 per cent, the prevalence in Colombia (39 per cent) and Ecuador (13 per cent) has consistently increased.
‘The epidemiology of the Mu variant in South America, particularly with the co-circulation of the Delta variant, will be monitored for changes.’
The WHO currently lists four Covid variants of concern — Alpha, Beta, Gamma and the highly-transmissible Delta.
Mu is the fifth variant of interest and is being tracked alongside Eta, Iota, Kappa and Lambda.
There is ‘no evidence’ to suggest the variant is more transmissible than the dominant Delta strain, Public Health England said last month.
UK health chiefs upgraded the strain to be a variant under investigation in July. Some 48 cases have already been detected so far.
Its key mutations include E484K, which can help it escape antibodies and is also found on the Beta and Gamma variants.
It also has the N501Y, which could help it spread easier. This mutation is also present in Alpha.
The coronavirus, called SARS-CoV-2, is mutating all the time as a result of genetic errors when it multiplies. Most mutations are harmless.
But ones that make it able to spread quicker or to survive longer inside the human body are the ones that are likely to stick around.
Covid: WHO warns of new ‘Mu’ variant found in Colombia – and it’s already been found in the UK