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

Common questions surrounding the newly authorized Pfizer vaccine include safety for teenagers and the risk of allergic reactions.

Though the final data doesn’t have conclusive data on 16 and 17 year olds because they weren’t enrolled in trials until more recently, the FDA is “very comfortable with the safety profile that was observed in 17 and 16 year olds," Peter Marks, director of the FDA’s Center for Biologics Evaluation and Research, told reporters.

Regarding allergies, Marks said 1.6% of the population has had a severe allergic reaction.

Marks said you should notify your doctor if you’ve ever had an allergic reaction to a vaccine and noted that sites that administer the vaccine will have medications on hand to respond to an allergic reaction.

ABC News’ Anne Flaherty contributed to this report.

FDA Commissioner Stephen Hahn on Saturday denied reports he was threatened with firing.

Sources familiar with the matter told ABC News that in a Friday phone call, White House chief of staff Mark Meadows suggested to Hahn that his job could be on the line if his agency didn’t authorize emergency use of the Pfizer-BioNTech vaccine by the end of the day.

“Representations in the press that I was threatened to be fired if we didn’t get it done by a certain date is inaccurate,” Hahn told reporters Saturday.

Hahn said he would “absolutely” take the Pfizer-BioNTech vaccine. He said it was authorized late Friday because science and data said it was ready, not because of “any other external pressure.”

ABC News’ Anne Flaherty contributed to this report.

A record number of people -- 3,309 -- died from COVID-19 Friday, according to new data from Johns Hopkins University.

Friday's record shattered the previous single-day record death toll of 3,124 which was set Wednesday.

An outbreak of COVID-19, resulting in 77 positive cases, has been traced to a youth basketball tournament held last month in California's Santa Clara County, public health officials said Friday.

At the tournament, held Nov. 7 and 8 at Courtside Basketball Center in Placer County, were 39 middle school and high school players, three coaches and 35 “additional contacts.”

Officials said it violated local and state orders for youth sports put in place during the coronavirus pandemic.

Another 17 cases outside the county have also been traced to the event, officials said in a news release.

“This outbreak is a troubling reminder that the widespread prevalence of COVID-19 in our community threatens all of us, and does not limit itself to geographic boundaries,” Dr. Monika Roy, Santa Clara County’s assistant public health officer, said in a statement.

“Public Health orders, directives, and guidance around contact sports and sporting events are in place for a reason. The risk of transmission in these settings can easily result in community spread that threatens the most vulnerable among us.”

The California Department of Public Health is investigating the incident, according to the news release, and Courtside’s website said the center is closed until further notice “out of precaution with the statewide lockdown and for the safety of all.”

The outbreak comes as California is seeing record numbers of COVID-19 cases during the holiday season.