Like any good supervillain, Omicron has an origin story. As Omicron continues to spread throughout the winter, scientists are learning more about where it came from, and how it became so dangerous. Interestingly, the Omicron variant is not related to the last two major strains of COVID—Alpha and Delta—but has been developing in the shadows. In fact, Omicron’s DNA is so different from other types of COVID that it’s hard to say anything for sure about where it came from.
Right now, there are three main theories. First, that Omicron had time to develop in a population that wasn’t closely monitored or treated for COVID. Second, that the variant mutated during a long-term infection of a specific patient. Or third, that it started by infecting animals, evolved, and then started infecting people.
While it’s too early to definitively pick one, there is some early evidence to support the second theory. That’s because Omicron is not just a mutated version of COVID, but has already mutated and evolved over previous versions of itself. This would suggest that the virus had to change to stay alive in a body that was learning to fight it. Still, it’s too early to say for sure.
Kupferschmidt, K. (2021b). Where did ‘weird’ Omicron come from? Science, 374(6572), 1179.
Specialist in internal medicine and primary care.