(CNN) The US reported more Covid-19 cases and deaths in the last week than any previous seven days during the pandemic, data showed Friday morning.
And more than 4,080 US coronavirus deaths were reported on Thursday alone -- the most ever reported in a single day during the pandemic and the first time the daily tally rose above 4,000, Johns Hopkins University (JHU) data showed.
In other words, even though the US is working to distribute vital Covid-19 vaccines -- a process criticized as being too slow -- the pandemic generally isn't showing signs of slowing down, and the virus is advancing with alarming speed in some areas, the White House coronavirus task force said in its report to states this week.
In Los Angeles County, where some ambulance crews have been reported to wait for hours with their patients outside hospitals because the facilities are overwhelmed, one person is dying of Covid-19 on an average of every eight minutes, officials said.
"We're seeing heroes in our hospitals, we're seeing angels in our ambulances, stretched thin to just deal with the onslaught right now," Los Angeles Mayor Eric Garcetti said Thursday.
Hospitals in the county are now preparing to ration care with triage officers who will decided which patients will receive care, with a focus of "doing the most good for the most people," according to new guidelines issued by the LA County Department of Public Health.
Texas reported record-high Covid-19 hospitalizations statewide for the fifth day in a row Thursday. Hospitals in Dallas County -- the state's second largest county -- had just 13 adult ICU beds available on Wednesday, County Judge Clay Jenkins said in a tweet.
The US has averaged about 228,400 Covid-19 cases a day over the last week as of Thursday -- an all-time high, and more than 3.4 times a summertime peak set in late July, JHU data shows.
And the country has averaged 2,764 deaths a day over the last week -- the highest figure of the pandemic, according to JHU data.
Hospitalizations also are soaring. Some 131,889 Covid-19 patients were in US hospitals on Friday -- the third-highest figure recorded, the Covid Tracking Project data show.
In a report this week, the White House coronavirus task force speculated there may be a "USA variant that has evolved here" that spreads more easily than the known variant.
"This fall/winter surge has been at nearly twice the rate of rise of cases as the spring and summer surges. This acceleration suggests there may be a USA variant that has evolved here, in addition to the UK variant that is already spreading in our communities and may be 50% more transmissible," the report said.
So far, there's no evidence of a US variant, the Centers for Disease Control and Prevention and academic researchers said Friday.
"Significant continued deterioration, from California across the Sunbelt and up into the Southeast, Mid-Atlantic and Northeast, despite low testing rates during the holidays, suggests aggressive community spread," the task force report said.
But a CDC spokesman said that "researchers have been monitoring US strains since the pandemic began, including 5,700 samples collected in November and December. To date, neither researchers nor analysts at CDC have seen the emergence of a particular variant in the United States" like those identified in the UK and in South Africa.
Trevor Bedford of the University of Washington and the Fred Hutchinson Cancer Research Center, who helps maintain a database of genetic mutations in the coronavirus, said he saw no evidence of a homegrown US strain that is spreading more aggressively.
The CDC did say at least 63 cases of a variant first identified in the UK have been recorded in eight US states. This includes at least 32 cases in California, 22 cases in Florida, three cases in Colorado, two cases in Connecticut, and one case each in Georgia, New York, Texas and Pennsylvania.
The agency says this does not represent the total number of cases circulating in the US, but rather just those that have been found by analyzing positive samples.
While vaccinations have been happening for several weeks, experts have said it will be months before they're widespread enough to make a meaningful impact in the pandemic's course.
Meanwhile, President-elect Joe Biden aims to release nearly every available dose of the coronavirus vaccine when he takes office, a break with the Trump administration's strategy of holding back half of US vaccine production to ensure second doses are available, CNN's Sara Murray reported Friday.
Releasing nearly all vaccine doses on hand could allow more people access to a first dose during a given time.
It could also be a risky strategy, as the vaccines from both Pfizer/BioNTech and Moderna require two doses, administered 21 days or 28 days apart, respectively, and vaccine manufacturing has not ramped up as rapidly as many experts had hoped.
"The second dose is absolutely critical," Dr. Anthony Fauci, director of the National Institute of Allergy and Infectious Diseases said Friday.
"The President-elect believes we must accelerate distribution of the vaccine while continuing to ensure the Americans who need it most get it as soon as possible. He supports releasing available doses immediately, and believes the government should stop holding back vaccine supply so we can get more shots in Americans' arms now," said TJ Ducklo, a spokesman for Biden's transition.
A transition official said the Biden team believes that vaccine manufacturers will be able to produce enough second doses in a timely fashion while administering first doses to more Americans.
The Trump administration has said it's necessary to hold back doses, to ensure Americans who receive the first course of the two-dose vaccine will be sure to have access to a second dose.
But that had sparked a debate about whether a better strategy would be releasing all available doses as quickly as possible, particularly amid rising death and hospitalization rates.
A study published Monday in the Annals of Internal Medicine found that administering first doses of a Covid-19 vaccine to more people quickly, instead of withholding available supply for use as a second dose, may reduce the number of new cases.
And World Health Organization advisers said Friday that a second dose of Pfizer and BioNTech's vaccine can be delayed as long as six weeks if need be. That's based on "currently available clinical trial data," the WHO guidance document said.
Moderna also believes a second dose of its vaccine can be given effectively 21 to 42 days after the first, a spokesperson for the company told CNN.
Kentucky Gov. Andy Beshear said Friday he agreed with Biden's plan, but wants "assurances the second dose will be there."
Nearly 6.7 million people have received their first doses of a vaccine and more than 22 million doses have been distributed, the CDC said Friday.
Federal officials had said 20 million people would have received first doses by the end of December.
Some health leaders said states need more money and more staff in order to be able to administer the vaccines fast enough.
Pennsylvania Secretary of Health Dr. Rachel Levine said states, cities and territories had been given just $340 million to build the infrastructure for vaccine rollouts up until the end of the year.
"That is clearly insufficient to accomplishing what we're trying to accomplish," Levine said.
President Donald Trump signed a $900 billion Covid-19 relief package in December that includes funds for vaccine rollout, something health leaders were "absolutely thrilled" about, Levine said.
The money will be "critical for several aspects of our response," Levine added, including contracting with companies to do community vaccine clinics.
The US Food and Drug Administration has alerted health care providers and labs that genetic variants of the novel coronavirus -- including an emerging variant first detected in the United Kingdom -- could lead to false negative Covid-19 test results.
False negative results can occur with any molecular test for the detection of the virus if a mutation has occurred in the part of the virus's genome that the test examines, the FDA said Friday.
But the risk that these mutations will impact overall testing accuracy is low, the FDA said. If Covid-19 is suspected after a negative test, repeat testing should be done with a different test, the agency recommends.
The agency noted three Covid-19 tests authorized in the United States may be impacted by genetic variants -- MesaBiotech Accula, TaqPath Covid-19 Combo Kit and Linea Covid-19 Assay Kit -- "but the impact does not appear to be significant."
Since the TaqPath and Linea Covid-19 tests detect multiple genetic targets, the overall test sensitivity should not be impacted, the FDA noted. However, if certain patterns emerge in individual results from those tests, labs might consider further genetic sequencing of specimens.
That "may help with early identification of new variants in patients to reduce further spread of infection," the FDA said in its letter to labs and health care providers, noting that the UK variant has been associated with an increased risk of transmission.
"The FDA will continue to monitor SARS-CoV-2 genetic viral variants to ensure authorized tests continue to provide accurate results for patients," FDA Commissioner Dr. Stephen Hahn said, referring to the name of the coronavirus that causes Covid-19.