The World Health Organization (WHO) recently added another version of coronavirus to its list of “variants of interest.”
The Mu variant, also known as B.1.621, was added to the WHO’s watchlist on August 30 after it was detected in 39 countries.
According to the WHO, Mu “has a constellation of mutations that indicate potential properties of immune escape.” Preliminary data suggests it may evade immune defences in a similar way to the Beta variant first discovered in South Africa, it said.
The Mu variant was first identified in Colombia in January 2021, where it accounts for 39 per cent of COVID cases. In neighbouring Ecuador, it accounts for 13 per cent of cases.
Beyond South America, cases have been reported in the UK, Europe, the US and Hong Kong. But the variant makes up less than 0.1 per cent of COVID infections globally.
“More studies are required to understand the phenotypic and clinical characteristics of this variant,” the WHO said, adding that the epidemiology of the Mu variant in South America, particularly with the co-circulation of the Delta variant, will be monitored for changes.
As of August 29, over 4,500 sequences (3,794 B.1.621 sequences and 856 B.1.621.1 sequences), genome sequences, analysed samples of the virus taken from patients, have been designated as Mu in the past four weeks. The sequences are used to track how it moves through the population, on an open-source genome repository, known as GISAID. Most of these have been reported in the US (2,065) and Colombia (852), Mexico (357) and Spain (473).
Meanwhile, South African scientists are closely monitoring the development of another new variant there. Scientists from National Institute for Communicable Diseases (NICD) and the KwaZulu-Natal Research Innovation and Sequencing Platform (KRISP) in South Africa said the potential variant of interest, C.1.2, was first detected in the country in May this year. C.1.2 has since been found in China, the Democratic Republic of the Congo, Mauritius, England, New Zealand, Portugal and Switzerland as of August 13, they said.
However, C.1.2 is not yet a variant to follow, nor a variant of concern, according to the classification of the World Health Organization. All viruses mutate over time and most mutations have little to no impact on the virus’ behaviour. The novel coronavirus pandemic has killed more than 45 lakh people globally, according to tracking data from Johns Hopkins University.