Covid-19: WHO monitoring 'Mu' variant among others

Geneva - The WHO said the variant has mutations that indicate a risk of resistance to vaccines.

The World Health Organization has said it is monitoring a new coronavirus variant known as 'Mu', which was first identified in Colombia in January.

Mu, known scientifically as B.1.621, has been classified as a "variant of interest", the global health body said Tuesday in its weekly pandemic bulletin.

The WHO said the variant has mutations that indicate a risk of resistance to vaccines and stressed that further studies were needed to better understand it.

"The Mu variant has a constellation of mutations that indicate potential properties of immune escape," the bulletin said.

There is widespread concern over the emergence of new virus mutations as infection rates are ticking up globally again, with the highly transmissible Delta variant taking hold -- especially among the unvaccinated -- and in regions where anti-virus measures have been relaxed.

All viruses, including SARS-CoV-2 that causes Covid-19, mutate over time and most mutations have little or no effect on the properties of the virus.

But certain mutations can impact the properties of a virus and influence how easily it spreads, the severity of the disease it causes, and its resistance to vaccines, drugs and other countermeasures.

The WHO currently identifies four Covid-19 variants of concern, including Alpha, which is present in 193 countries, and Delta, present in 170 countries.

Five variants, including Mu, are to be monitored.

After being detected in Colombia, Mu has since been reported in other South American countries and in Europe.

The WHO said its global prevalence has declined to below 0.1 percent among sequenced cases. In Colombia, however, it is at 39 percent.

South Africa detects new coronavirus variant

South African scientists have detected a new coronavirus variant with multiple mutations but are yet to establish whether it is more contagious or able to overcome the immunity provided by vaccines or prior infection.

The new variant, known as C.1.2, was first detected in May and has now spread to most South African provinces and to seven other countries in Africa, Europe, Asia and Oceania, according to research which is yet to be peer-reviewed.

It contains many mutations associated in other variants with increased transmissibility and reduced sensitivity to neutralising antibodies, but they occur in a different mix and scientists are not yet sure how they affect the behaviour of the virus.

Laboratory tests are underway to establish how well the variant is neutralised by antibodies.

South Africa was the first country to detect the Beta variant, one of only four labelled "of concern" by the World Health Organization (WHO).

Beta is believed to spread more easily than the original version of the coronavirus that causes Covid-19, and there is evidence vaccines work less well against it, leading some countries to restrict travel to and from South Africa.

Richard Lessells, an infectious disease specialist and one of the authors of the research on C.1.2, said its emergence tells us "this pandemic is far from over and that this virus is still exploring ways to potentially get better at infecting us".

He said people should not be overly alarmed at this stage and that variants with more mutations were bound to emerge further into the pandemic.

Genomic sequencing data from South Africa show the C.1.2 variant was still nowhere near displacing the dominant Delta variant in July, the latest month for which a large number of samples was available.

In July C.1.2 accounted for 3 per cent of samples versus 1 per cent in June, whereas Delta accounted for 67 per cent in June and 89 per cent in July.

Delta is the fastest and fittest variant the world has encountered, and it is upending assumptions about Covid-19 even as nations loosen restrictions and reopen their economies.

Lessells said C.1.2 may have more immune evasion properties than Delta, based on its pattern of mutations, and that the findings had been flagged to the WHO.

A spokesman for South Africa's health department declined to comment on the research.

South Africa's Covid-19 vaccination campaign got off to a slow start, with only around 14 per cent of its adult population fully vaccinated so far.

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