BRITAIN has reported nearly 50 cases of Mu Covid variant which has now been formally labelled as a 'variant of interest' by WHO, reported The Daily Mail.
However, cases due to the variant remain low overall as a proportion of all cases amid the spread of the Delta variants, the report added.
The variant with the scientific name B.1.621 was first detected in Colombia in January, and almost 4,000 cases have been spotted since then in more than 40 countries.
According to WHO, the Mu variant may be more resistant to vaccines, as was the case with the South African 'Beta' variant. There are fears it may be more infectious, too.
Last month, Public Health England said that there is 'no evidence' to suggest the variant is more transmissible than the dominant Delta strain.
"The epidemiology of the Mu variant in South America, particularly with the co-circulation of the Delta variant, will be monitored for changes," it said.
UK health chiefs upgraded the strain to be a variant under investigation in July. A PHE study previously suggested it could make vaccines less effective. But UK health chiefs said more research was needed.
In the US, cases of the Mu variant made up almost one per cent of infections in July but the number of infections then declined in August amid the spread of the Delta variant, The Mail report added.
According to WHO, 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.
"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," WHO said.
The world health body 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.