President Donald Trump speaks during a news conference in the Rose Garden of the White House, July 14, 2020, in Washington.
President Donald Trump speaks during a news conference in the Rose Garden of the White House, July 14, 2020, in Washington.

U.S. President Donald Trump hailed progress toward an effective vaccine against the coronavirus on Friday, in his first public remarks in six days since the media projected former Vice President Joe Biden as winner of the November 3 election.  

Trump, who has refused to concede the election, spoke from the White House Rose Garden but did not take any questions from reporters.

He called work on the vaccine the greatest mobilization of vaccine development in U.S. history, noting that it usually takes more than eight years to produce an effective inoculation.

FILE PHOTO: A woman holds a small bottle labeled with a "Coronavirus COVID-19 Vaccine" sticker and a medical syringe in front of displayed Pfizer logo.

On Monday, pharmaceutical giant Pfizer announced it had created a vaccine that was 90% effective against the coronavirus, leading Trump to tweet “SUCH GREAT NEWS.” The vaccine candidate must still complete testing and receive approval from the U.S. Food and Drug Administration.

In his remarks, Trump for the first time acknowledged uncertainty about the next administration, saying his administration would not order another lockdown “under any circumstances,” but suggesting Biden would order one if he is in power.

“Hopefully whatever happens in the future, who knows, which administration it will be, I guess time will tell, but I can tell you this administration will not go to a lockdown,” Trump said.

President-elect Joe Biden speaks Nov. 10, 2020, in Wilmington, Del.

Biden has not yet said whether he would order a lockdown to control the spread of the coronavirus.

Biden said in a statement Friday that he met with members of his transition COVID-19 Advisory Board, who presented “alarming” facts about the “accelerating public health crisis.”

“Our country is experiencing surges in reported infections, hospitalizations and fatalities all over the country, with virtually nowhere getting spared,” he said.

Biden added that “this week's news on progress toward a safe and effective COVID-19 vaccine is positive, but it will be many months before there is widespread vaccination in this country.”

The coronavirus has killed more than 244,000 Americans. Cases have recently been increasing across the country with new daily totals of more than 100,000 confirmed cases for more than a week.

Trump has made one other public appearance since the media projected Biden the winner of the presidential election. On Wednesday, he went to Arlington National Cemetery to mark Veterans Day but made no remarks.

The president has refused to concede the race, citing irregularities in several swing states. One battleground state, Georgia, is recounting its ballots by hand, and the president has filed lawsuits in several other states though none so far that might affect the outcome of the election.