The Omicron variant of the coronavirus has spread to at least 19 U.S. states, but seems less severe than the Delta variant, though more time is needed to gain a fuller picture, top U.S. health officials said on Tuesday. "It's too early to be able to determine the precise severity of disease, but inklings that we are getting, and we must remember these are still in the form of anecdotal, but it appears that with the cases that are seen, we are not seeing a very severe profile of disease," said Dr. Anthony Fauci, chief medical advisor to the U.S. president, during a White House briefing.