(CNN) The US reported more than 80,000 new coronavirus infections Friday -- the highest daily case number since the pandemic began.
That comes amid other bleak patterns including rising hospitalizations and daily death tolls across the country, with experts warning that the worst is yet to come.
Friday's case count of at least 80,005 surpasses the country's previous one-day high of 77,362, reported July 16, according to Johns Hopkins University.
US Surgeon General Dr. Jerome Adams cautioned earlier Friday that hospitalizations are starting to go up in 75% of the jurisdictions across the country, and officials are concerned that in a few weeks, deaths will also start to increase.
The good news, Adams said, is that the country's Covid-19 mortality rate has decreased by about 85% thanks to multiple factors, including the use of remdesivir, steroids and better management of patients.
More than 41,000 Covid-19 patients were in hospitals across the country Thursday, according to the Covid Tracking Project. This is the highest level of nationwide coronavirus hospitalizations since August 20.
The number of people hospitalized has increased by 33% since the beginning of October, the CTP says.
Deaths are also creeping upward, with 856 on Thursday, Johns Hopkins says. The seven-day average of daily deaths has climbed to 763 -- the highest average in a month.
In White House coronavirus task force reports obtained by CNN this week, officials say there are "early signs of deterioration in the Sun Belt and continued deterioration in the Midwest and across the Northern States." And more state leaders have sounded the alarm on increasing infections, hospitalizations and deaths.
Dr. Anthony Fauci, the nation's leading infectious disease expert, said Friday that he's concerned about a massive surge in Covid-19 cases across the country and urged people to "double down" on measures to prevent the spread of the virus.
"The upticks on the map of more than 30 States that are having upticks is not going to spontaneously turn around unless we do something about it," Fauci, the director of the National Institute of Allergy and Infectious Diseases, told CNN's Erin Burnett.
Fauci has previously said he doesn't think a federal mask mandate would work but on Friday he said it might be time for it -- even if such a rule would be tricky to enforce.
"Well, if people are not wearing masks, then maybe we should be mandating it," Fauci said.
Drug manufacturer AstraZeneca announced Friday it will resume the trial of its experimental coronavirus vaccine in the US.
The company said the US Food and Drug Administration has given approval to continue the trial after reviewing all of the global safety data and concluding it was safe to resume.
The trial was paused last month after a volunteer in clinical trials in Britain developed a neurological condition.
"This is going to be the most scrutinized vaccine ever produced," Adams said Friday referring to a potential Covid-19 vaccine.
While President Donald Trump said Thursday that he is hopeful that a vaccine will be approved before the end of the year, the director of the National Institutes for Health remains "cautiously optimistic."
NIH Director Dr. Francis Collins said Friday that "it might not happen and it might take longer."
"FDA is not going to approve a vaccine that has less than 50% effectiveness," Collins said Friday during a National Press Club virtual event.
But even if it's approved, it's unclear whether Americans will take it. Collins said he's troubled to see that the percentage of people willing to take the vaccine appears to be failing.
"I've been talking so optimistically about how we are likely to have a vaccine by the end of the year, but if only 50% of Americans are interested in taking it, we're never going to get to that point of immunity across the population where Covid-19 goes away. It could be here for years," Collins said.
Only 51% of Americans said they would try to get a Covid-19 vaccine once one is widely available at a low cost, according to a CNN poll conducted by SSRS earlier this month.
Data from the Covid Tracking Project and Johns Hopkins also show:
• At least eight states reported record-high hospitalizations Thursday: Kentucky, Nebraska, North Dakota, Ohio ,Oklahoma, South Dakota, Wisconsin and Wyoming.
• At least 12 states saw their highest seven-day averages of new daily cases: Alaska, Colorado, Idaho, Illinois, Indiana, Kentucky, Minnesota, Montana, Ohio, Oklahoma, Utah, and Wyoming.
• And at least six states -- Colorado, Indiana, Montana, Ohio, Oklahoma and Utah -- reported their highest daily case counts.
In North Carolina, more than 100 cases have been linked to a church convocation even in Charlotte, health officials said Friday.
At least three deaths and a cluster of 12 cases at a senior living community have been linked to the events earlier this month at the United House of Prayer for All People, Mecklenburg County officials said.
In Nashville, Tennessee, hospitals are reporting a 40% increase in patients. Hospital officials say a major surge of new Covid-19 cases could threaten their ability to serve patients with many diagnoses requiring hospitalization.
Social gatherings in Colorado will be limited to 10 people from no more than two households after a surge in coronavirus cases, health officials announced Friday.
The decision was based on case data showing that attending social gatherings and community exposures has become more common among new cases since July.
"We are asking all Coloradans to act with an abundance of caution to reverse these worrying trends," Colorado Department of Health and Environment Executive Director Jill Hunsaker Ryan said in a statement. "We need to keep gatherings smaller and with people from fewer households — we are asking everyone to 'shrink their bubble' to reduce the spread."
Maryland Gov. Larry Hogan said Thursday family gatherings are the top source of transmission in his state.
Experts fear the holidays might raise infections. Doctors worry that college students returning home could bring the virus, with large family gatherings for Thanksgiving and other events adding to the spread. Infectious disease experts say virtual celebrations might be best this year.
US Health and Human Services Secretary Alex Azar said Friday that household gatherings have become a "major vector" of coronavirus spread.
"This is being driven by individual behaviors at this point," he told CNN's Jim Sciutto. "We've got to keep focused on washing our hands, watching our distance and wearing our face coverings when we can't watch our distance, and in particular being careful in household gatherings."
The University of Washington's Institute for Health Metrics and Evaluation says the "fall/winter surge has begun" -- just a couple weeks behind Europe -- and will intensify in November and December before reaching a peak in January.
"Many states will face enormous pressure on hospital capacity and will likely have to re-impose some social distancing mandates," IHME said. "The best strategy to delay re-imposition of mandates and the associated economic hardship is to expand mask use."
The IHME said in another study Friday that if 95% of Americans wore masks in public, more than 100,000 lives could be saved through February.
The study notes that about 49% of US residents report that they "always" wear a mask in public.
At that rate and with states continuing to remove social distancing mandates, the US death toll could reach about 1 million by February 28, according to the study.