EXPLAINER: Boosters key to fight omicron, lot still to learn

The new omicron variant took only a few weeks to live up to dire predictions about how hugely contagious it is

The new omicron variant took only a few weeks to live up to dire predictions about how hugely contagious it is but scientists don’t yet know if it causes more severe disease even as the world faces exploding cases just before Christmas.

“Everything is riskier now because omicron is so much more contagious,” said Dr. S. Wesley Long, who directs the testing lab at Houston Methodist Hospital — and over the past week has canceled numerous plans to avoid exposure.

Omicron now is the dominant variant in the U.S., federal health officials said Monday, accounting for about three-quarters of new infections last week.

The speed that it's outpacing the also very contagious delta variant is astonishing public health officials. In three weeks, omicron now makes up 80% of new symptomatic cases diagnosed by Houston Methodist’s testing sites. It took the delta variant three months to reach that level, Long said.