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