By Christina Maxouris, CNN

(CNN) -- The United States on Thursday surpassed 17 million official Covid-19 cases across the pandemic, while a key meeting currently underway could lead to authorization of a second coronavirus vaccine for the country.

Thursday's developments come as the US, while just starting to distribute its first authorized vaccine this week, is dealing with record rates of daily cases, daily coronavirus deaths and numbers of Covid-19 patients in hospitals.

Vaccine advisers to the Food and Drug Administration began meeting Thursday morning to discuss Moderna's vaccine candidate, and are expected to vote Thursday afternoon on whether to recommend it.

If the advisory panel does recommend it -- as it did for Pfizer's vaccine last week -- the FDA is widely expected to quickly grant emergency use authorization, which would free Moderna's vaccine for shipment.

The US Centers for Disease Control and Prevention would need to approve the vaccine before shots can be administered -- and a CDC advisory panel is expected to meet on the matter Saturday, raising the possibility that the Moderna vaccine could be used next week.

Hundreds of American health care workers have received their first dose of the Pfizer vaccine and many states have announced they're also expecting nursing home resident vaccinations to begin this week.

And on Wednesday, the FDA said people administering that vaccine may squeeze out extra doses from the vials if there is leftover solution in them after giving the standard five doses.

Politico was first to report that some pharmacists found they could get six -- and possibly even seven -- doses of vaccine out of vials, which are each designed to provide five doses. An FDA spokeswoman told CNN the agency was aware of the issue and "working with Pfizer to determine the best path forward."

"At this time, given the public health emergency, FDA is advising that it is acceptable to use every full dose obtainable (the sixth, or possibly even a seventh) from each vial, pending resolution of the issue," the spokeswoman said. "However, since the vials are preservative-free, it is critical to note that any further remaining product that does not constitute a full dose should not be pooled from multiple vials to create one."

More than 2.9 million doses were allocated to states for the first Pfizer vaccine doses, according to a list published Wednesday by the CDC. Another more than 2.9 million will be available for second doses about 21 days later.

The first vaccinations and a possible green light for Moderna are all good news. But the pandemic raging in the US is still far from over -- and more brutal than ever.

Wednesday saw grim numbers -- the highest Covid-19 infections and deaths the country has reported in a single day, and the highest number of Covid-19 patients in US hospitals on a given day.

More than 247,000 new cases were reported Wednesday. More than 113,000 Covid-19 patients were in hospitals, according to the COVID Tracking Project. And more than 3,600 people were added to the nation's death toll.

The country's total official case count stood at more than 17,000,400 on Thursday, according to Johns Hopkins University only five days after the count surpassed 16 million. But researchers have said the actual number of US infections -- counting those that weren't tested for -- probably is many millions higher.

'Still at a dangerous and critical' part in pandemic

While there's been some progress in slowing the spread of the virus in the northern and central US, according to the White House coronavirus task force, cases are still surging in more populated states.

"Stabilization in the Northern Plains, Upper Midwest, and some Rocky Mountain and Heartland states is being offset by significant deterioration in more populous states (82% of the population)," reports sent to states by the task force and obtained by CNN said.

And now, Americans have important choices to make: the upcoming holidays could help drive another surge of cases, hospitalizations and, inevitably, deaths, if people opt to travel and gather again. Despite a warning from the CDC before Thanksgiving urging against travel, more than four million spent the holiday away from home.

In California, where Los Angeles County health officials continue to report exploding case numbers, health services director Dr. Christina Ghaly attributed the surge to residents gathering over the Thanksgiving holiday despite repeated pleas to stay home.

And the worst is yet to come, Ghaly added, saying "we are still in for a very rough few weeks at least, and potentially through January."

Governors across the Northeast and Midwest issued a video message this week encouraging residents to "double down" on safety measures and reconsider their holiday plans.

"If you are planning to travel or gather with other households for the holidays -- we urge you to reconsider," the governors said. "Just one infection can cause an outbreak in your community, which could overwhelm our hospitals and put you and your loved ones at risk."

In hopes of helping curb the spread around the holidays, El Paso County Judge Ricardo Samaniego announced curfews from 10 p.m. to 5 a.m. lasting from December 23 to December 26 and from December 30 to January 4.

"What people need to know is, we are still at a dangerous and critical part of this pandemic, and tens of thousands of American lives are at stake," Adm. Dr. Brett Giroir, assistant secretary for health at the Department of Health and Human Services, said Wednesday.

"If you can avoid traveling, that's a good measure," he added.

More Covid-19 at home tests authorized

Meanwhile, the FDA also issued an emergency use authorization Wednesday for another at-home Covid-19 test -- this one for Abbott's BinaxNOW COVID-19 Ag Card Home Test.

The test is authorized for "prescription use at home with self-collected nasal swab samples from individuals ages 15 years or older who are suspected of Covid-19 by their health care provider within the first seven days of symptom onset," a statement from the agency reads. Adults can take samples for younger children.

Abbott has said the new test will cost $25.

"FDA continues to authorize Covid-19 tests that will give more Americans access to greater testing flexibility and options," FDA Commissioner Stephen Hahn said.

That comes a day after the FDA also gave emergency use authorization to a $30 over-the-counter test made by Ellume that people can take home and give to themselves.

On Wednesday, Giroir said there will likely be more good news from the FDA soon about "other home tests that are not exactly the over-the-counter type but are in the same ballpark."

"You'll see more and more tests get authorized, and then ramping up very soon in the early part of the year," he added.