Officials in the health sector are monitoring a new coronavirus variant, "mu," that they claim has concerning mutations that could enable it to escape vaccine-induced immune suppression.
According to the World Health Organization, B.1.621 was first identified in Colombia in January 2021. It was identified by WHO as a "variant or interest" (VOI) on Monday, August 30th.
Live Science previously reported that the VOI label indicates that the variant is becoming more common in many areas and may have mutations that could affect viral characteristics such as transmission or severity. Officials use the term "variant or concern," or VOC to describe a variant that has an increased transmissibility, as with the delta variant, or other worrying features like the ability to evade vaccinations.
Officials from WHO wrote that the mu variant "has an assortment of mutations which indicate potential properties of immuno escape" in Tuesday's WHO epidemiological report on COVID-19. This was published Tuesday, August 31. The report stated that laboratory data shows that antibodies produced in response to COVID-19 vaccinations or prior infection are less able "neutralize," (bind to and disable) the mu variant. Future studies will confirm this finding. According to Medpage Today, Mu shares some mutations (a VOC), such as mutations known E484K or K417N.
The mu variant has been found in 39 countries so far. This includes large outbreaks in Europe and South America. According to Medpage Today, the variant was also detected in the United States. A University of Miami study found that the variant was present in 9% of the Jackson Memorial Health System's cases. The variant is less than 0.1% in all COVID-19 cases that undergo genetic sequencing worldwide, but it accounts for 39% and 13% of the sequenced cases in Colombia, according to the report. It has also been increasing in prevalence in these areas.
WHO stated that more research is needed to understand the mu variant better and monitor its spread.
Although it is not known exactly how transmissible mu may be, Public Health England recently observed that the variant doesn’t seem to be spreading rapidly and that it seems "unlikely” to be more transmissible to the delta variant. In a risk assessment, Public Health England stated that "there is no evidence that [mu] out-competing Delta" at the moment. The assessment stated that the variant's ability "may contribute to future growth changes" due to vaccine-induced immunity.
WHO currently monitors five variants (eta.iota.kappa.lambda.mu) and four variants (alpha.beta.gamma.
Original publication on Live Science
