Coronavirus updates: 84% of California population to go on lockdown Sunday night

Dr. Anthony Fauci told MSNBC Americans should expect some protection after getting the first vaccine shot, but in general, they'll be "good" about 7 to 10 days after receiving the second dose.

For Pfizer's vaccine, the doses are given three weeks apart, according to Business Insider.

Regarding children and the vaccine, the director of the National Institute of Allergy and Infectious Diseases predicted trials could start in January with older children before moving on to trials on younger children. Because the vaccine will have been shown to be safe in adults, the trials for children can be relatively smaller and can move faster, he said.

“If we start in January, a couple to three months after that” we could have a vaccine for older children, Fauci said. Then additional trials would need to be done on younger children, he said.

-ABC News' Anne Flaherty

New York City will receive 465,525 vaccine doses this month, with the focus on health care workers and nursing home residents first, Mayor Bill de Blasio said.

After that, de Blasio said he wants to prioritize the neighborhoods hardest hit, as well as public housing residents.

The first shipments from Pfizer are expected to arrive as early as Dec. 15 while doses from Moderna, if approved on time, are set to arrive as early as Dec. 22, the mayor said.

New York City’s seven-day positivity rate stands at 5.19%.

-ABC News' Aaron Katersky

An additional 2,804 deaths from COVID-19 were registered nationwide on Wednesday -- the highest recorded death toll on a single day for the U.S., according to a real-time count kept by Johns Hopkins University.

The latest daily death toll shatters the previous record of 2,609 new deaths on April 15, according to Johns Hopkins data.

The nations death toll now stands at 273,590.

There were 200,007 new cases of COVID-19 confirmed in the U.S. on Wednesday, according to Johns Hopkins -- the 30th straight day that the U.S. reported over 100,000 newly diagnosed infections, and only the second time since the start of the pandemic that the figure has exceeded 200,000. Wednesday's count is just under the country's peak of 205,557 new cases recorded last Friday, according to Johns Hopkins data.

Over 13.9 million people in the U.S. have been diagnosed.

Former Presidents Barack Obama, George W. Bush and Bill Clinton have offered to get vaccinated in front of cameras if it will help show Americans they can trust the science.

Bush's chief of staff, Freddy Ford, told CNN, "The vaccines need to be deemed safe and administered to the priority populations. Then, President Bush will get in line for his, and will gladly do so on camera."

Clinton's press secretary, Angel Urena, told CNN on Wednesday, "President Clinton will definitely take a vaccine as soon as available to him, based on the priorities determined by public health officials. And he will do it in a public setting if it will help urge all Americans to do the same."

Obama told SiriusXM host Joe Madison this week, "If Anthony Fauci tells me this vaccine is safe, and can vaccinate, you know, immunize you from getting COVID, absolutely, I'm going to take it."

"I may end up taking it on TV or having it filmed, just so that people know that I trust this science, and what I don't trust is getting COVID," Obama said.