Omicron’s Radical Evolution

Thirteen of Omicron’s mutations should have hurt the variant’s chances of survival. Instead, they worked together to make it thrive.

As nurses and doctors struggle with a record-breaking wave of Omicron cases, evolutionary biologists are engaged in a struggle of their own: figuring out how this world-dominating variant came to be.

When the Omicron variant took off in southern Africa in November, scientists were taken aback by its genetic makeup. Whereas earlier variants had differed from the original Wuhan version of the coronavirus by a dozen or two mutations, Omicron had 53 — a shockingly large jump in viral evolution.

In a study posted online last week, an international team of scientists further deepened the mystery. They found that 13 of those mutations were rarely, if ever, found in other coronaviruses, suggesting they should have been harmful to Omicron. Instead, when acting in concert, these mutations appear to be key to some of Omicron’s most essential functions.