While the delta variant continues causing a surge of COVID-19 cases and hospitalizations in the United States, epidemiologists around the world are trying to learn as much as they can as quickly as they can about omicron, labeled a variant of concern by the World Health Organization Nov. 26. Other variants of concern have come and gone—and this may be true of omicron as well. But omicron is particularly worrisome because it has mutated more than 30 times and has been associated with an increase in cases in South Africa, where it was first detected (though it is believed to have originated elsewhere on the continent).