Mysteries of omicron variant could take weeks to untangle

A pandemic-weary world faces weeks of confusing uncertainty as countries restrict travel and take other steps to halt the newest potentially risky coronavirus mutant before anyone knows just how dangerous omicron really is.

Will it spread even faster than the already extra-contagious delta variant? Does it make people sicker? Does it evade vaccines’ protection or reinfect survivors? There are lots of guesses but little hard evidence as scientists race to find answers amid scrutiny from an anxious public.

Omicron raised alarm because of its sheer number of mutations, more than prior variants had. Possibly 30 are in a key place, the spike protein that lets the virus attach to human cells. Scientists have little data yet on whether omicron causes more severe disease than other variants. And while it already has been diagnosed in numerous countries just days after its discovery was announced, it’s also too soon to know how contagious it is.