The World Health Organization has recorded a new coronavirus “variant of interest” named Mu (B.1.621). The strain is being closely monitored by WHO according to the United Nations press service.
It is warned that the new coronavirus strain was becoming increasingly prevalent in Colombia and Ecuador, where it is now responsible for around 39% and 13% of infections, respectively., and showed signs of possible resistance to vaccines.
Mu was first identified in Colombia in January 2021, and since then, there have been “sporadic reports” of cases and outbreaks in South America and Europe.
Mu is the fifth variant of interest to be monitored by the WHO since March. It has a number of mutations that suggest it could be more resistant to vaccines, the health agency warned, but stressed that further research would be needed to confirm this. Preliminary data show a reduced effectiveness of vaccines “similar to that seen for the Beta variant”. The WHO said it would be monitoring “the epidemiology of the Mu variant in South America, particularly with the co-circulation of the Delta variant…for changes”
Published in late July in the Journal of Medical Biology, a study by doctors of the University of Biomedical University of Rome and the University of Brescia showed a good resistance to the "Mu" strain of patients who received Pfizer/Biontech vaccine. In their opinion, this variant of coronavirus does not pose a threat to the effectiveness of the vaccine, Interfax reports.
However, in its weekly epidemiological update published on Tuesday, WHO did not rule out that the new version of "Mu" has a number of mutations that indicate its higher vaccine resistance.
As of 29 August, 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 U.S (2,065) and Colombia (852), Mexico (357) and Spain (473).