Health experts have warned of a "viral blizzard" in the United States as the new Omicron variant spreads rapidly nationwide and has already been found in at least 41 states.

In recent weeks, COVID-19 cases, deaths and hospitalizations have all surged in the country, with many parts experiencing high levels of community transmission, according to the U.S. Centers for Disease Control and Prevention (CDC).

The current seven-day daily average of COVID-19 cases is about 122,000, a 1.5-percent increase from the previous week, according to the latest CDC data, which also showed the seven-day average of daily deaths is about 1,180, up 8.2 percent from the prior week.

Currently, the United States is witnessing about 7,800 new hospital admissions each day, a 4.4-percent increase from the previous week, the data showed.

The Omicron variant, which is possibly more contagious than the Delta variant, had been found in at least 41 U.S. states as of Friday, since the first case in the country was detected in California on December 1.

There is a two- to three-week lag between sample collection for SARS-CoV-2 testing to producing and analyzing sequence data, so it is likely that more U.S. infections with Omicron from late November will be detected over the coming days, according to the CDC.

Top U.S. infectious disease expert Anthony Fauci said the Omicron variant is going to be dominant in the United States, given its doubling time. There is "virtually no" protection against the Omicron variant without getting booster shots, he said Friday.

"The more people get vaccinated, the less severe this Omicron outbreak will be. 160,000 unvaccinated people have already needlessly lost their lives just since June, and this number will continue to go up until the unvaccinated take action," said White House COVID-19 Response Coordinator Jeff Zients on Friday.

Despite the increased attention for Omicron, Delta continues to be the main variant circulating in the United States. For the week ending December 11, the Delta variant accounted for 96.7 percent of circulating SARS-CoV-2 variants, according to the CDC.

Holiday travel rush has already begun amid Omicron concerns. The U.S. Transportation Security Administration expected up to 21 million Americans will fly between December 23 and January 3.

"As we head into the holiday season, when many will be gathering with their loved ones, I want to again encourage everyone to utilize the proven prevention strategies that keep everyone safe: get vaccinated and get boosted, mask in public indoor settings, physical distancing, handwashing, improve ventilation, and testing to slow transmission," said CDC Director Rochelle Walensky.

(With input from Xinhua News Agency)