Trump celebrates Pfizer announcing a successful COVID-19 vaccine, days after he lost the US election

• President Donald Trump celebrated Pfizer's Monday-morning announcement of promising results for its COVID-19 vaccine.
• On Monday morning, he wrote on Twitter that it was "SUCH GREAT NEWS!"
• His post about the vaccine news was a departure from his recent posts dedicated to baselessly disputing his reelection loss.
• Pfizer's head of vaccine research and development emphasized to The New York Times that the company did not take federal money to develop the vaccine.

President Donald Trump celebrated Pfizer's Monday-morning announcement that its COVID-19 vaccine had succeeded in late-stage trials, news that broke on the first business day after he lost the US presidential election.

Trump tweeted on Monday morning: "STOCK MARKET UP BIG, VACCINE COMING SOON. REPORT 90% EFFECTIVE. SUCH GREAT NEWS!"

—Donald J. Trump (@realDonaldTrump) November 9, 2020

His tweet came after Pfizer announced that its vaccine, which it is producing with the German company BioNTech, was found to be more than 90% effective in preventing COVID-19 during its final stage of clinical trials.

Pfizer's data has not been peer reviewed, and it still needs to do more work to prove the safety of the vaccine.

But the announcement was a major step in the fight to stop the virus, which has killed more than 1.2 million people, put billions of people under lockdown, and hammed the global economy.

Pfizer said it planned to apply for emergency approval for the vaccine, though it is not clear how long that process would take.

Trump also pointed to gains in the stock market in his tweet.

Global stocks have hit record highs after Biden's win, and US stock futures then soared Monday morning after Pfizer's announcement.

The US has been the world's worst-affected country in terms of cases and deaths, with Trump widely criticized because of it.

Trump himself was hospitalized with COVID-19, and the White House has seen multiple outbreaks.

Trump lost the presidential election to former Vice President Joe Biden last week.

Trump's tweet about the vaccine was markedly different in tone from the rest of his tweets over the weekend, in which he repeated baseless claims that the election was subject to widespread fraud and that Democrats "stole" the election.

Biden on Monday unveiled a new coronavirus advisory board, doing so two days after most major networks called the presidential race in his favor and with Trump still yet to concede.

"The American people deserve an urgent, robust, and professional response to the growing public health and economic crisis caused by the coronavirus (COVID-19) outbreak," Biden said in a statement on his transition website.

Biden congratulated Pfizer on Monday, but noted that widespread vaccination will not happen for "many more months."

Pfizer has distanced itself from the US government's coronavirus program rolled out under Trump, called Operation Warp Speed, which aims to speed up coronavirus vaccine development.

The operation has promised Pfizer $1.95 billion to deliver 100 million doses for Americans, but Kathrin Jansen, Pfizer's head of vaccine research and development, emphasized to The New York Times that the company did not take federal money to develop the vaccine.

"We were never part of the Warp Speed," told the Times. "We have never taken any money from the U.S. government, or from anyone."