https://apnews.com/e338ab4c30b68025dbc049c36838f357

With coronavirus cases rising in parts of Europe and Asia, scientists worry that an extra-contagious version of the omicron variant may soon push cases up in the United States too.

Experts are also keeping their eyes on another mutant: a rare delta-omicron hybrid that they say doesn't pose much of a threat right now but shows how wily the coronavirus can be.