Coronavirus updates: 1st vaccines now on the way to all 50 US states

The U.S. had its "worst week yet" during the pandemic in terms of COVID-19 deaths, according to an analysis by the COVID Tracking Project. 

The seven-day average of reported deaths per day surpassed 2,000 this week for the first time since the spring. As of Dec. 9, that number was 2,281, a new record.

New COVID-19 deaths also set a record high this week, with 3,088 reported on Thursday.

As the number of new cases and current hospitalizations continue to climb, "the worst is yet to come," the COVID Tracking Project warned.

"Given the rapid increase in the number of new cases, we expect the metrics for hospitalizations and deaths to continue to rise in the coming weeks -- especially if in-person gatherings over Thanksgiving led to increased spread of the novel coronavirus, as public health experts warned," it said.

An independent advisory panel of infectious disease experts, doctors and scientists recommended Thursday that the U.S. government authorize the nation's first vaccine for people over the age of 16.

It's a major milestone in the effort to get the vaccine to hospitals and pharmacies.

After hours of drilling down into data produced from a clinical trial involving 44,000 people, the group of experts -- known as the Vaccines and Related Biological Products Advisory Committee -- voted in favor of the vaccine for people over 16 years of age.

Several members raised concerns about unknowns about the vaccine, including its potential to trigger allergic reactions and little data on how it impacts pregnant women.

Several panel members also expressed concern there wasn't enough data to support giving the vaccines to 16- and 17-year-olds.

At issue was this question: "Based on the totality of scientific evidence available, do the benefits of the Pfizer-BioNTech COVID-19 Vaccine outweigh its risks for use in individuals 16 years of age and older?"

The panel voted 17-4 that the benefits outweighed the risks. One member of the committee abstained.

The U.S. Food and Drug Administration will now take the committee's input into account in issuing an emergency use authorization.

-ABC News' Anne Flaherty

Indoor dining and gyms will be suspended in Pennsylvania beginning Saturday, Gov. Tom Wolf announced.

Indoor gatherings will be limited to 10 people, he said.

Wolf announced the new restrictions one day after revealing that he tested positive for COVID-19.

Pennsylvania has over 422,000 confirmed cases and has lost at least 12,010 residents to the virus.

California reported 220 deaths on Thursday, surpassing the previous record of 219 on July 31.

With the average daily number of deaths climbing over the last month, the state's death toll now stands at 20,463.

California Gov. Gavin Newsom has ordered regions to follow a stay-at-home order if their intensive care unit capacity falls below 15%.

The San Joaquin Valley -- where capacity is at 1.9% -- and Southern California -- where capacity is at 7.7% -- are under stay-at-home orders until at least Dec. 28.

The Greater Sacramento region now meets the criteria and a stay-at-home order will go into effect Thursday night.

Just two regions, the Bay Area and Northern California, are not under stay-at-home orders.

ABC News’ Matt Fuhrman contributed to this report.