(CNN) President Joe Biden said Thursday that he's tested positive for Covid-19 but will continue to work while in isolation at the White House despite his mild symptoms.
In a video posted to Twitter, Biden told Americans that he is "doing well" and that his symptoms continue to be mild.
"I guess you heard, this morning I tested positive for Covid. But I've been double vaccinated, double boosted. Symptoms are mild and I really appreciate your inquires and concerns. But I'm doing well, getting a lot of work done. Going to continue to get it done and in the meantime, thanks for your concern and keep the faith. It's gonna be OK," Biden, who was unmasked while standing outside on the Truman Balcony, said in the 20-second video the White House says was filmed by a masked and socially distanced videographer.
The mild symptoms and diagnosis protocol for Biden -- a double-boosted 79-year-old at high risk for experiencing severe illness -- will mean isolating and "working and resting" at the White House residence for the rest of the day, according to a senior administration official. This is the first time Biden has tested positive for Covid-19, and he last tested negative on Tuesday, per White House press secretary Karine Jean-Pierre.
Biden has called several people in the hours since his diagnosis. He wrote on Twitter Thursday afternoon that he is "doing great" following the positive test and said he called Pennsylvania politicians to send his regrets about having to cancel a scheduled trip to the commonwealth. The tweet was accompanied by an image of the President smiling at a desk, without a mask, in the residence of the White House.
In a memo that was sent to staff obtained by CNN, White House chief of staff Ron Klain said Biden will be working over the phone and on video conference for the next few days following the positive result.
"I've spoken to him several times this morning already about an array of matters, and he is focused on our pending business," Klain wrote on Thursday.
Biden tested positive for Covid-19 Thursday morning and has begun taking the antiviral drug Paxlovid, which is available via emergency use authorization from the US Food and Drug Administration for treatment of mild to moderate Covid-19 in people 12 and older who are at high risk of severe illness. It requires a doctor's prescription.
"Consistent with (US Center for Disease Control and Prevention) guidelines, he will isolate at the White House and will continue to carry out all of his duties fully during that time," Jean-Pierre said in a statement.
Thursday marks "Day 0" of the President's Covid-19 timeline -- meaning he will be in isolation until at least next Tuesday in accordance to the CDC's guidelines.
The President's symptoms include "rhinorreha (or 'runny nose') and fatigue, with an occasional dry cough, which started yesterday evening," according to a letter from the President's physician, Dr. Kevin O'Connor. Biden did not have a fever Thursday morning, White House coronavirus coordinator Dr. Ashish Jha told CNN.
Jha later told reporters that Biden's oxygen levels were "normal" as of Thursday morning and that Biden's Covid-19 virus sample has been sent to a lab to identify the specific variant he is infected with. Results are expected in "less than a week."
Biden first tested positive for Covid-19 on an antigen test Thursday morning as part of routine screening, and the positive result was later was confirmed by a PCR test, his physician said.
O'Connor also noted that the President met the FDA's criteria for use of the antiviral Paxlovid, adding, "I anticipate that he will respond favorably, as most maximally protected patients do."
Due to his age, Biden is at an increased risk for a more severe case of Covid-19, although the CDC says older adults being fully vaccinated and boosted significantly reduces their risk of hospitalization and death.
Jha said Thursday that Biden has the "full set of protections" to deal with Covid-19 at his advanced age.
"The bottom line is given how much immunity he has from vaccines, given that he was started on treatments right away ... I think all of those things very dramatically reduce his risk of serious illness," Jha told CNN's Jeff Zeleny during the White House press briefing. "And that's really the goal here, is to prevent serious illness, to keep that risk as low as possible. I think he's gotten that full set of protections."
Biden received his first two doses of the Pfizer/BioNTech Covid-19 vaccine ahead of his inauguration in January 2021, his first booster shot in September and his second booster vaccination on March 30.
Vice President Kamala Harris and first lady Jill Biden tested negative on Thursday.
Jean-Pierre indicated that the West Wing will continue to practice its current protocols but that the White House residential staff will be taking measures to create a "very minimal footprint" to avoid infecting others.
The number of aides who staff the White House residence will be reduced to the "bare minimum" in light of Biden's positive Covid-19 diagnosis, an official told CNN.
And a mid-level West Wing aide who works in close proximity to Biden and was on his recent trip to the Middle East also tested positive for Covid-19, according to two sources familiar. The person is not considered a close contact of the President and tested positive earlier this week.
Harris is expected to keep her normal schedule while Biden isolates. The senior administration official said there are no plans and no need to transfer executive powers to Harris -- as was done last November for 85 minutes, when Biden was under anesthesia for a routine colonoscopy.
Harris has been identified as a close contact of Biden, a White House official told CNN. Harris last saw Biden on Tuesday and tested negative on Thursday. She is a close contact, an additional aide says, because they spent more than 15 minutes together while being briefed on the presidential daily brief. The White House official added that Harris will follow CDC guidelines for those who are vaccinated, including wearing a well-fitting mask while around people for 10 days from the date of the last close contact.
The first lady and the vice president said they had both spoken to the President on Thursday following the diagnosis.
Jill Biden told reporters in Detroit earlier Thursday that she had spoken to the President and that "he's doing fine. He's feeling good."
The first lady, her spokesman Michael LaRosa told CNN, will keep her original schedule on Thursday, which includes a stop in Georgia before heading to Wilmington, Delaware. She is also double boosted, LaRosa said.
And Thursday afternoon, Harris said at an event in North Carolina that the President "is in good spirits."
"He is working from the White House residence and when he spoke he was very pleased that we are all together today," she told her audience, adding that Biden told her to "tell everybody hello."
A White House official told CNN that Biden's scheduled travel to Wilkes-Barre, Pennsylvania, later on Thursday for a speech on crime prevention has been canceled. A DNC fundraiser Biden was scheduled to headline Thursday night has been postponed, officials said.
It's yet to be determined whether the event will be rescheduled or if donors will be asked to make their pledged contributions.
Biden was also scheduled to travel to Orlando and Tampa, Florida, on Monday, but now he's expected to be isolating.
Biden has ramped up his engagement with the public over the past year as the White House has shifted its approach toward the pandemic. On Wednesday, Biden traveled to Somerset, Massachusetts, for an event on climate executive actions, where he was seen shaking hands and greeting attendees in the outdoor crowd.
The President's positive diagnosis comes less than a week after a swing through the Middle East, where he held meetings with world leaders in Israel and Saudi Arabia. While abroad, Biden was seen shaking hands, bumping fists and embracing other leaders.
The White House is currently working on contact tracing for those who may have been close contacts of Biden, per an official, since his positive Covid test. They plan to inform any close contacts on Thursday, including members of Congress and the press.
At least one member of Congress who was a close contact after seeing Biden in Massachusetts received a contact tracing call from the White House on Thursday.
The White House reached out to the lawmaker's office Thursday afternoon, according to a source familiar, and advised the member of Congress to follow the CDC recommendations for what an individual should do when they're determined to be a close contact.
One of the recommendations, for example, for someone who is fully vaccinated and was a close contact is to wear a well-fitting mask while around other people for 10 days from the date of last close contact.
White House officials have been preparing for months for what many viewed as the inevitability that Biden would come down with Covid.
A wave of cases -- including among Harris, White House staffers and members of Congress -- has swept Washington through the spring and summer. And as more and more of his top officials and members of his family contracted Covid, officials came to believe it was possible the President himself would get sick, even as they took steps to shield him from the virus.
Klain, in his Thursday memo to staff, wrote that White House officials "have said for some time that there was a substantial possibility that the President -- like anyone else -- could get Covid, and we have prepared for this possibility. We are now executing on our plan so that the President can continue to work seamlessly from the Residence."
Biden last underwent an annual physical in November at Walter Reed National Medical Center. O'Connor wrote in a memo at the time that the President remained "fit for duty, and fully executes all of his responsibilities without any exemptions or accommodations."
Officials had a loose plan in place for the day Biden tested positive, including informing the public when the tests were confirmed and releasing a letter from Biden's physician -- which both took place on Thursday.
Then-President Donald Trump issued a 1 a.m. ET tweet on October, 2, 2020, announcing that both he and then-first lady Melania Trump had tested positive for Covid-19. And Biden officials have been mindful of how the previous administration handled Trump's diagnosis and have been intent on being more forthcoming about Biden's condition.
Now, more than two years into the pandemic, Biden has become the second sitting US president to test positive for Covid-19. His mild symptoms so far stand in stark contrast to Trump's diagnosis before a vaccine was available in 2020 -- a Covid infection that led to a multi-day hospitalization at Walter Reed.
The President's infection comes as Covid cases are once again on the rise in the US, driven by the most contagious strain of the virus yet -- BA.5. More than 1 million people have died of Covid-19 across the country since the pandemic began.
The Biden administration is continuing the Covid-19 public health emergency as it seeks new funding from Congress for treatments and vaccines. The public health emergency declaration allows many Americans to obtain free Covid-19 testing, therapeutic treatment and vaccines. Medicare has also relaxed the rules governing telehealth so that many more seniors can access such services during the declaration. And states are not involuntarily disenrolling residents from Medicaid during the declaration, in exchange for receiving more generous federal matching funds.
This story has been updated with further developments on Thursday.