The number of COVID-19 patients in U.S. hospitals is again at an all-time high -- and the U.S. Center of Disease Control and Prevention director says this kind of strain is setting the stage for "the most difficult time in the public health history of this nation."

More than 98,600 COVID-19 patients were in U.S. hospitals Tuesday -- the most counted during the pandemic, according to the COVID Tracking Project.

"The reality is, December and January and February are going to be rough times. I actually believe they're going to be the most difficult time in the public health history of this nation, largely because of the stress that's going to be put on our health care system," Dr. Robert Redfield, the director of the CDC, said Wednesday.

Hospital systems across the country have for weeks said their capacity and staffing are being stretched too thin, and that patient care may suffer as a result.

That includes New Mexico, where the state's largest health care provider says it is virtually out of open beds -- ICU and otherwise -- at its nine hospitals.

While those hospitals have been stretching capacity -- by opening up new areas for beds, creating more double occupancy rooms and bringing in staff from outside its own system -- "we are out of levers to pull," Dr. Jason Mitchell, chief medial officer of Presbyterian Healthcare Services in New Mexico, told CNN.

"When you run out of resources -- whether that's doctors or nurses or beds or ventilators -- you cannot give (the best) care. ... We are not there yet (but) we are very close as a state."

Daily coronavirus cases and deaths also have been soaring.

The U.S. has averaged 161,448 new cases daily over the last week -- nearly 2.5 times the summertime peak in July.

And the U.S. on Tuesday recorded its second-highest one-day tally of COVID-19 deaths: 2,597,according to Johns Hopkins University. The only day to top that daily total was April 15, when six more deaths were recorded.

The country's daily average of COVID-19 deaths across a week is 1,531 -- above its summer high of around 1,130 but lower than the pandemic peak above 2,240 in late April.

But as coronavirus hospitalizations rise, the number of daily deaths is predicted to get worse, with various experts recently warning that it could regularly surpass 2,000 and 3,000, and perhaps approach 4,000.

Health experts say they expect cases and hospitalizations to swell further in the coming weeks, when infections from Thanksgiving gatherings start to manifest.

And the CDC, like it did for Thanksgiving, is recommending that people postpone travel over the upcoming winter holidays, CDC COVID-19 incident manager Dr. Henry Walke said Wednesday.

100 million Americans could be vaccinated by February, Operation Warp Speed adviser says

The world appears to be moving closer to available COVID-19 vaccines: The United Kingdom on Wednesday became the first Western nation to approve one, and the first doses are expected to be be rolled out across that country starting next week.

And two companies are preparing to ship out vaccines in the United States, anticipating the U.S. Food and Drug Administration will give them emergency approval this month.

Initial supplies in both countries will be limited, and the wider population won't have access to them until months into 2021. A CDC panel recommended Tuesday that heath care and long-term care workers get inoculated first.

Vaccine candidates from Pfizer and Moderna are awaiting emergency use authorizations in the US, with an FDA panel expected to meet about whether to authorize them on December 10 and December 17, respectively.

Assuming the vaccines are authorized, the vaccines' first shipments could happen December 15 and 22, respectively, according to a document from the federal government's Operation Warp Speed.

By February, 100 million Americans could be vaccinated against coronavirus, Moncef Slaoui, chief adviser to Operation Warp Speed, said Wednesday.

"All the investments we have made in scaling up and starting to stockpile manufacturing of the vaccines allow us to stay confident that we will be able to distribute 20 million vaccines, enough to vaccinate 20 million people in the U.S. in December," Slaoui told a news briefing.

The United States has said if both Pfizer and Moderna win FDA emergency use authorization in December, they could distribute 40 million doses of vaccine by the end of the month. Each vaccine requires two doses, so that's enough to fully vaccinate 20 million people.

Slaoui said he expected 60 million more vaccines by the end of January.

CDC: 14-day quarantine can be shortened to 7-10 days

New guidance from the CDC says quarantine periods can be shorter than 14 days for some people exposed to COVID-19.

CDC continues to recommend quarantining for 14 days as the best way to reduce the risk of spreading COVID-19, said Walke, the CDC COVID-19 incident manager.

But there are "two acceptable alternative" quarantine periods: Quarantine can end after 10 days without a COVID-19 test if the person reported no symptoms, or after seven days with a negative test result if the person has reported no symptoms. People who have been exposed should still watch for symptoms for 14 days, especially if they end quarantine earlier, Walke said.

"I want to stress that we are sharing these options with public health agencies across the country, so that they can determine how long quarantine period should last in their jurisdictions based on local conditions and needs," Walke said. "Everyone should follow this specific guidance from their local public health authorities about how long they should quarantine."

Reducing the length may make it easier for people to quarantine, Walke said, and lessen stress on the public health system as new infections are rising quickly.

States push back against climbing records

Tuesday was a record-breaking day for coronavirus devastation in many states, and local leaders are pushing back with new measures to combat the virus.

Oregon reported its highest number of deaths reported in a day. Texas set its record for coronavirus cases reported in one day, at more than 15,000. And Mississippi has more COVID-19 patients in hospitals than ever before, at more than 1,000, state officials said.

Mississippi since late October has had a mask mandate in certain counties where the spread of the virus was worst. The governor added 13 counties to that list -- meaning the mandate is now in 65% of the state's counties.

"This is a time when the virus is extremely present," Gov. Tate Reeves told reporters. "The risk is higher of catching it because of the number of cases that we're reporting, there is more virus in the communities."

Kentucky Gov. Andy Beshear called Tuesday the state's "worst day ever" for the coronavirus by "virtually every measure."

"It is the deadliest day that we have had," Beshear said. "If we don't all do our part, if we try to be the exception, then slowing down this thing won't work, and we will lose a lot more Kentuckians we love and care about."

California's Los Angeles County also had its "worst day" yet when it came to cases and hospitalizations, according to county Health Director Dr. Barbara Ferrer.

"However, it will likely not remain the worst day of the pandemic in Los Angeles County. That will be tomorrow, and the next day and the next as cases, hospitalizations and deaths increase," she said.

A modified stay-at-home order went into effect in the county Monday, prohibiting outdoor dining and gathering with people outside a single household.