Health officials say Omicron less severe than Delta, spreads to 19 U.S. states

Special: Battle Against Novel Coronavirus

The Omicron variant of COVID-19 has spread to at least 19 U.S. states, seemingly less severe than Delta, and it will take more time to get a fuller picture of it, 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 Anthony Fauci, chief medical advisor to the U.S. president, during a White House briefing.

"In fact, it might be and I underscore might be, less severe as shown by the ratio of hospitalizations per number of new cases," added the top infectious doctor.

In addition, Fauci noted that the virus also appears more transmissible, saying that "real-world evidence is accumulating rapidly, literally on a daily basis, to allow us to determine increase in cases, possible increase in reproductive number and the rapid replacement of Delta by Omicron in certain situations."

He cautioned that the results that are in so far may have been influenced by the relative youth of the patients in South Africa who contracted the new strain of the coronavirus. This could potentially have masked the variant's severity, since younger people tend not to display as serious symptoms from COVID-19 as older patients.

Also on Tuesday, the U.S. Centers for Disease Control and Prevention (CDC) Director Rochelle Walensky said that the Omicron variant has been found in 50 countries and at least 19 states across the United States, after it prompted global travel restrictions and fresh vaccine mandates since its discovery in southern Africa last month.

"While we are still working to understand the severity of Omicron as well as how it responds to therapeutics and vaccines, we anticipate that all of the same measures will at least, in part, provide some protection against Omicron," said Walensky, stressing again her call to get vaccinated.

While the number of Omicron cases is expected to rise in the United States, the most recent data show that more than 99 percent of coronavirus samples that have been genetically sequenced showed the Delta variant, she said, adding that it is too early to know whether Omicron will become dominant against Delta or not.

White House COVID-19 Response Coordinator Jeff Zients said that vaccinations have surged with roughly 12.5 million shots administered over the last week, 7 million of which were booster shots.

"That's the highest weekly total number of shots since May," he said. "So we're now vaccinating people in numbers we haven't seen since the spring."

As of Tuesday afternoon, 236,363,835 people had received at least one dose of COVID-19 vaccine, making up 71.2 percent of the whole U.S. population; fully vaccinated people stood at 199,687,439, accounting for 60.1 percent of the total. A total of 47,866,620 people, 24 percent of the fully vaccinated group, had received booster shots, according to the CDC.