Data indicate omicron is milder, better at evading vaccines

The omicron variant appears to cause less severe disease than previous versions of the coronavirus, and the Pfizer vaccine seems to offer less defense against infection from it but still good protection from hospitalization, according to an analysis of data from South Africa, where the new variant is driving a surge in infections.

While the findings released Tuesday are preliminary and have not been peer-reviewed — the gold standard in scientific research — they line up with other early data about omicron’s behavior, including that it seems to be more easily...