COVID-19 updates: LA has highest daily death total since April

Omicron is estimated to account for 98.3% of new cases in the U.S. as of Jan. 8, according to new data released by CDC Tuesday. (These figures are calculated using modeling and may not be exact.)

Delta now accounts for only 1.7% of new cases nationally, forecasters estimate.

In three areas of the country -- the deep South, the Southeast and the New York/New Jersey region -- omicron is estimated to account for more than 99% of new cases.

In early December, omicron was estimated to account for just 0.6% of all new cases. 

-ABC News' Arielle Mitropoulos

The White House has been limiting its in-person gatherings to 30 people "over the last several weeks" due to the omicron surge, White House press secretary Jen Psaki said.

“We wear masks in the West Wing at all times, including in your office, unless you're in your office alone,” Psaki said.

-ABC News' Ben Gittleson

Dr. Anthony Fauci and Republican Kentucky Sen. Rand Paul engaged in a heated exchange at a Tuesday Senate hearing on COVID-19.

When Paul claimed Fauci was attacking scientists who disagreed with him, Fauci responded, "you keep distorting the truth."

"I brought together a group of people to look at every possibility with an open mind ... you're completely turning it around," Fauci said.

Fauci said the purpose of the committee was to get help to the American public, but he said Paul instead chooses to "keep coming back to personal attacks on me that have absolutely no relevance."

Fauci told the Senate committee on Health, Education, Labor and Pensions that Paul's attacks are "for political reasons" and inspire "the crazies out there."

Fauci referenced the December arrest of a California man who, at a traffic stop, was allegedly found with an AR-15 style rifle, loaded magazines, boxes of ammunition and body armor. Prosecutors said the driver downloaded TikTok videos, compiling a list of people he allegedly wanted to kill, including Fauci and former Presidents Bill Clinton and Barack Obama.

The U.S. daily death average from COVID-19 is steadily rising, with an average of 1,550 new fatalities each day -- up by about 44% since Christmas, according to federal data.

This average is still significantly lower than last winter when the nation peaked at about 3,400 deaths per day.

Indiana now has the nation's highest death rate, followed by Delaware and Wyoming.

Nearly 146,000 Americans with COVID-19 are currently in hospitals -- a pandemic high -- according to new data from the Department of Health and Human Services.

On average, more than 18,500 virus-positive Americans are being admitted to the hospital each day, a figure which has more than doubled over the last month. It's still not clear how many COVID-19-positive people in hospitals were admitted to the hospital for the virus or admitted for other reasons and coincidentally tested positive.

About 30% of hospitals (with available data) are facing critical staffing shortages.

-ABC News' Arielle Mitropoulos