The US has reported its highest one-day Covid-19 death tally: Over 2,800

(CNN) More than 2,800 Covid-19 deaths were reported Wednesday in the United States -- the most the country has ever reported in a single day -- as health care officials say their staff and facilities are struggling to support burgeoning numbers of patients.

The number of Covid-19 patients in US hospitals Wednesday -- 100,226, according to the COVID Tracking Project -- also is the highest reported on a given day during the pandemic.

One-day death totals can draw from delayed reports across several days. Still, recently soaring daily rates of infections and hospitalizations has various experts predicting the daily death count could regularly surpass 2,000 or 3,000, and perhaps approach 4,000.

The country's daily average of Covid-19 deaths across a week is 1,654 -- above its summer high of around 1,130 but lower than the pandemic peak above 2,240 in late April.

"By this time next week, we are going to be talking about 3,000 deaths a day -- that's 9/11 every single day," Dr. Jonathan Reiner, a cardiologist and professor of medicine at George Washington University, told CNN on Wednesday.

The death count reported Wednesday was 2,804, surpassing the previous one-day high of 2,603 set on April 15, according to Johns Hopkins University data. Earlier, JHU's total for Wednesday was higher -- but that count was corrected Thursday morning because of an error found in one state's tally.

Daily coronavirus cases and hospitalizations also have been soaring -- prompting hospital and other officials to warn they're running out off staff and capacity to adequately care for patients.

"We have stretched our health care worker staff as far as we can, and it will get to the point where the quality of care will be severely hampered if, in fact, we don't have these health care workers," Michael Osterholm, director of the Center for Infectious Disease Research and Policy and a member of President-elect Joe Biden's transition Covid-19 advisory board, said Thursday.

As for cases: The country's average number of new daily Covid-19 cases across a week was 164,103 Wednesday -- nearly 2.5 times the summertime peak in July, JHU data show.

Health experts say they expect cases and hospitalizations to swell further in the coming week, when infections from Thanksgiving-week gatherings may noticeably accumulate.

"We're not even going to see those (Thanksgiving) numbers until this weekend (or) early next week," Dr. Leana Wen, CNN medical analyst and former Baltimore health commissioner, said Thursday. "And I think at this point it's really important for us to flatten that (case) curve again, hunker down, stay at home and certainly not have any indoor gathering (or) non-essential travel."

Los Angeles tells residents to 'cancel everything'

States and communities across the US are racing to adjust to the skyrocketing number of coronavirus hospitalizations.

In Los Angeles, Mayor Eric Garcetti said Wednesday that If the virus continues to spread there at its current rate, Los Angeles will run out of hospital beds by Christmas. He called on residents to "hunker down" and "cancel everything" to help stop the spread.

A modified stay-at-home order began this week in Los Angeles County, prohibiting for three weeks all in-person dining and gathering with people outside a single household.

The county's daily count of new cases rose by 224% in November's first three weeks, and hospitalizations are up over 85% from two weeks ago, county health officials said Wednesday.

"The public health condition of our city is as dire as it was in March in the earliest days of this pandemic," Garcetti said Wednesday, adding that the number of daily infections in Los Angeles has tripled since early November and hospitalizations are at a new peak.

In southwestern Kansas, no staffed ICU beds are available, Gov. Laura Kelly said Wednesday.

"While case numbers may have dipped slightly, the strain on our hospitals and health care workers has not," she said.

Coronavirus hospitalizations in Nevada have been climbing daily since November, with few exceptions, and were at a peak Wednesday with 1,652 people hospitalized, the state's data dashboard showed.

CVS says it will be ready for priority vaccine distribution as early as December 15

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

Pharmacy chain CVS plans to be ready to serve some of those groups as soon as December 15, should the approvals come, company chief medical officer Dr. Troy Brennan said Thursday.

Though details need to be hammered out with the CDC and individual states, the federal government has contracted with CVS and Walgreens to vaccinate long-term care facility residents and staff if vaccines are approved.

"Our plan is to be ready to go as early as December 15, waiting for the state approvals," Brennan said.

Vaccine candidate elicits at least 119 days of immune response, researchers say

Moderna's coronavirus vaccine candidate can elicit an immune response that lasts at least 119 days, researchers reported Thursday.

The data, described in a letter to the editor published in The New England Journal of Medicine, suggests that the mRNA-1273 vaccine produced high levels of antibodies that continued to be detected in volunteers 119 days after the first vaccination.

The data came from a study of 34 healthy adults who received two injections of vaccine at a dose of 100 micrograms, 28 days apart.

At the 100-microgram dose, "mRNA-1273 produced high levels of binding and neutralizing antibodies that declined slightly over time, as expected, but they remained elevated in all participants 3 months after the booster vaccination," the researchers wrote. "Serum neutralizing antibodies continued to be detected in all the participants at day 119."

Those are the antibodies that find, attach to and stop the virus from infecting cells.

The researchers -- from the National Institute of Allergy and Infectious Diseases, Emory University School of Medicine and Moderna, among other institutions -- noted that no serious adverse events were reported in the trial.

The researchers also noted that their findings support the use of a 100-microgram dose of mRNA-1273 in an ongoing Phase 3 trial, which recently found the vaccine to have a 94.5% efficacy rate.

Correction: An earlier version of this story had a higher death tally for Wednesday, citing data from states that Johns Hopkins University was reporting at the time. The total was lowered to 2,804 on Thursday morning after JHU discovered an error with one state's count for Wednesday.