Mu variant: A novel coronavirus variant of new concern to WHO

While the world continues to face the Delta variant of the coronavirus, which is more infectious than the earlier Novel Coronavirus strain, the World Health Organization (WHO) says another variant is spreading in parts of South America and is more likely to reduce the effectiveness of the currently circulating vaccine.

The official name of the virus is B.1.621, and the WHO nominating rules use Greek letters for different variants, so it is also known as the Mu variant.

According to WHO, as of 31 August, confirmed cases of COVID-19 related to the Mu variant virus have been received from 39 countries or territories, with a total of about 4,500 cases. In Asia, public reports indicate that cases of the strain have been detected this week in Hong Kong, Taiwan, South Korea and elsewhere.

The WHO officially listed the strain as a “variant of concern” on Aug. 30, citing variations in its genetic sequence that suggest it may be capable of evading the immune system, but stressing that more research is needed to better understand its clinical features.

“All viruses, including the Novel Coronavirus, mutate over time,” the WHO said. “None of these mutations will change the nature of the virus, but some of them can change its infectivity, lethality and ability to resist vaccines and drugs.”

The Mu variant was first discovered in The South American country of Colombia in January this year. Local health officials say the strain has become the most prevalent novel Coronavirus variant.

Agence France-Presse quoted Colombian officials as saying that two-thirds of the 700 people who die from the virus each day on average are infected with the Mu variant of the virus, which caused a third outbreak in the country between April 6 and 6.

About 125,000 people have died of COVID-19 in Colombia since the outbreak began.
Local officials described the new strain as “highly contagious,” but did not say which was more contagious than the Delta strain.

As of Friday (3 September), Hong Kong had detected three confirmed cases of COVID-19 linked to the Mu variant virus, two imported from Colombia and one from the United States. One imported case from the United States involved a patient who had received two doses of the BioNTech vaccine.

Taiwan officials said On Thursday (2 September) that there had been a case of Mu variant infection in a patient who had returned from the United States and who had also received two doses of forbutai vaccine.

Experts generally agree that vaccination remains the most effective form of protection against novel Coronavirus.

Ho Pak Leung, an infectious disease researcher at the University of Hong Kong, told local media that the genetic map of the Mu variant showed several local variations. Past experience has shown that the mutation impairing levels of neutralizing antibodies produced by COVID-19 vaccines. But he stressed that vaccination was still the most powerful control tool.