The World Health Organization classified a new COVID-19 strain as a variant of concern Aug. 30. The strain, named mu, was first detected in Colombia in January, according to the WHO's weekly COVID-19 epidemiological update.
Five things to know:
1. B.1.621, the strain's scientific name, has since been identified in at least 39 countries, including the U.S., though its global prevalence is below 0.1 percent based on sequenced cases.
2. Mu is most prevalent in Colombia and Ecuador, where it accounts for 39 percent and 13 percent of cases, respectively, and has consistently been on the rise in those countries, according to the report.
3. The strain carries "a constellation of mutations that indicate potential properties of immune escape," though further research is needed.
4. It's not yet known whether mu is more transmissible or if it causes more severe illness
5. Early data suggests the strain has characteristics that allow it to evade some protection offered by current vaccines or monoclonal antibody treatments, similar to levels seen in other variants such as beta.