For now, there’s no evidence that Omicron causes more severe disease than previous variants. And it’s also not clear yet how quickly Omicron can spread from person to person.
Some earlier variants, such as Beta and Mu, had evolved a strong ability to evade immune defenses. But they never became a serious threat to the world because they proved to be poor at transmitting.
Some mutations in Omicron suggest that it may indeed transmit well. Three mutations alter a region of the spike protein called the furin cleavage site, which is already known to help the spike protein attach more effectively to cells.
But Dr. Hanage said he was not yet convinced by the South African data that Omicron was running rampant across the country. “I think it’s too early to be definitive,” he said.
New 'Omicron' Variant Stokes Concern but Vaccines May Still Work – The New York Times https://t.co/g6iYz3Rqto
— Scott Gottlieb, MD (@ScottGottliebMD) November 27, 2021