As the Delta variant continues to advance worldwide, a new coronavirus variant has been classified by the World Health Organization. It is B.1.621, or Mu, identified for the first time in Colombia.
"Based on the latest round of evaluations, on Aug. 30 2021, B.1.621 was classified as a variant of concern and was named 'Mu.' This includes the Pango B.1.621.1 descendant lineage. The variant is known as 21H in scientific nomenclature," the organization said on Wednesday, Sept. 1 in its weekly epidemiological newsletter about the evolution of the pandemic.
Although more studies are still needed to better understand the characteristics of this new variant, B.1.621 has a number of mutations that could present resistance to vaccines.
Maria van Kerkhove, Technical Director for COVID-19 said on Twitter that "4,500 sequences from 39 countries have been uploaded, meaning that at least 4,500 people worldwide have been infected, tested and genomic testing has shown that they are infected with the Mu variant."
The Mu mutation was first detected in Colombia in January 2021 and later in other South American countries and in Europe.
"Since its first detection in Colombia in January 2021, there have been some sporadic reports of Mu variant cases and some larger outbreaks have been reported in other South American countries and in Europe," the UN agency said.
Currently, the new variant concentrates the highest number of confirmed cases in Colombia and Ecuador, where about 39% and 13% of the total number of infected people have it, respectively, according to the WHO report.
Mu in the United States
Dr. Anthony Fauci, chief epidemiologist of the U.S. Government, said on Thursday, Sept. 2 that they are "closely" watching the Mu variant, although it has not been considered "an immediate threat at this time."
"We are paying attention to it, we take all of that seriously, but we don't consider it an immediate threat at this time," Fauci said during a press conference of the White House COVID-19 response team.
Fauci also mentioned that the presence of the Mu variable in the country is "not even close to being dominant," unlike the Delta variant, which is already found in more than 99% of its territories.