Covid: WHO warns of new ‘Mu’ variant found in Colombia – and it has already been found in UK
The bosses of the World Health Organization are now officially following another variant of Covid 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, and it has spread to more than 40 countries.
Almost 50 cases of Mu have been spotted in Britain so far and hundreds have been identified in the United States.
The WHO weekly bulletin claimed that its mutations suggest it may be more resistant to vaccines, as was the case with the South African ‘Beta’ variant. There are also fears that it is more contagious.
But the agency warned that more studies would be needed to examine this further, with the WHO now officially calling Mu a “variant of interest.”
Almost 4,000 cases of the variant have been detected so far since its onset in January, but the number of infections has declined in recent weeks, coinciding with the rapid increase in the Delta variant. This graph shows the seven-day average proportion of Mu variant cases worldwide. They reveal that its prevalence has recently declined
The variant was first spotted in Colombia in January. It has since been detected in 40 countries
Some 48 cases have already been detected so far, according to Public Health England
In Britain, nearly 50 cases have been spotted so far. But these have remained low overall amid the spread of the Delta variant. The graph above shows variant B.1.621 as a proportion of all UK detected cases by date
In the United States, it made up nearly 1% of infections in July, but the number of infections then declined in August amid the spread of the Delta variant.
In Colombia – where it was first identified – it is still behind by around six out of ten cases. But the proportion of cases it represents in the country has also started to decline.
The WHO report said: “Since it was first identified in Colombia in January 2021, there have been a few sporadic reports of Mu variant cases and larger outbreaks have been reported in other countries in North America. South and Europe.
“Although the global prevalence of Mu variant among sequenced cases has declined and is currently below 0.1%, the prevalence in Colombia (39%) and Ecuador (13%) has steadily increased.
What is the ‘Mu’ or B.1.621 variant?
Where were the cases detected?
This mutant strain was first spotted in Colombia in January.
It has since spread to more than 40 countries, including the UK, US, France, Japan and Canada.
Is its prevalence increasing?
There have been 4,000 cases detected to date, but this is considered an underestimate as many countries that have experienced epidemics have little monitoring for variants.
The number of cases blamed on the variant declined globally over the past month, amid the spread of the Delta strain.
In Colombia – where it was first detected – it is still behind around six in ten infections.
Can the strain dodge vaccine-triggered immunity?
The variant carries the E484K mutation, which can help it escape antibodies.
This change is also found on the South African “Beta” variant and the Brazilian “Gamma” variant.
A PHE study previously suggested that this could make vaccines less effective. But British health chiefs said more research was needed.
“The epidemiology of the Mu variant in South America, particularly with the co-circulation of the Delta variant, will be monitored for changes.”
WHO currently lists four variants of Covid of concern – Alpha, Beta, Gamma and the highly transmissible Delta.
Mu is the fifth variant of interest and is followed 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.
WHO infectious disease epidemiologist Maria van Kerkhove tweeted: “Mu’s circulation is down around the world and he [makes up] less than 0.1% of the currently shared Mu sequences, but this requires careful observation. “
“The monitoring and evaluation of variants is ongoing and of critical importance to understanding the evolution of this virus, in combating Covid and adapting strategies as needed.”
British health chiefs upgraded the strain to a variant under investigation in July.
Some 48 cases have already been detected to date.
Its key mutations include E484K, which can help it escape antibodies and is also found on beta and gamma variants.
It also has the N501Y, which might help it spread more easily. This mutation is also present in Alpha.
The coronavirus, called SARS-CoV-2, mutates all the time as a result of genetic errors when it multiplies. Most mutations are harmless.
But the ones that make it able to spread faster or survive longer inside the human body are the ones that are likely to stick around.
More than 300 variants of Covid have been detected to date.
It comes after a PHE report released in early August suggested that Covid jabs may be “less effective” against the mutant strain.
But they said their conclusions were based on preliminary laboratory evidence, so the data was “very limited and more research is needed.”
Their report added that there was “no evidence” to suggest that the variant is more transmissible than the Delta strain.
The report said: “The threat level of such a variant depends on its growth and expansion.
“There is currently very low certainty about the growth estimates, but in the current environment, there is no indication that it exceeds Delta. ”