The scientific community reacted positively overall – although the trial is still ongoing and the vaccine candidate would need to be stored in specialist deep freezers, creating huge supply chain complications.

The vaccine candidate is one of more than 40, but no other developer has yet made similar claims about effectiveness.

There was also promising news from Brussels, where the EU parliament and member states struck a deal to pass the bloc’s multi-annual budget, unblocking €750 billion (US$886 billion) in coronavirus recovery funds.

Dacian Ciolos, head of the parliament’s centrist Renew Europe Group, called the agreement “a game-changer” for Europeans facing adversity from the pandemic.

The novel coronavirus has infected close to 51 million people worldwide, with more than 1.2 million deaths.

On Tuesday, 6,867 new deaths were recorded worldwide, with the highest daily tolls in France, Spain and the United States.

The US remains the hardest-hit nation at more than 10 million cases and nearly 240,000 deaths, with shocking new data now including a record 60,000 current hospitalisations.

Coronavirus: vaccine hopes rise on promising Pfizer-BioNTech trials

“We’re still facing a very dark winter,” Biden said.

Trump had clashed repeatedly with his own government experts, often refusing to back restrictions or even wear a mask in public. After the Pfizer announcement, he claimed – without evidence – that the news was delayed until after the election to damage him.

There was a separate breakthrough when the US Food and Drug Administration on Monday granted emergency approval to a synthetic antibody treatment developed by the pharmaceutical company Eli Lilly.

Bamlanivimab, which was shown to reduce the risk of hospitalisation and emergency room visits, is the first major drug to be approved that was designed specifically for the coronavirus.

Despite encouraging news on the medical front, rising infection and death rates have left many governments struggling to cope.

Brazil’s President Jair Bolsonaro – who has downplayed the virus even as it has killed 163,000 people in his country – lashed out with a homophobic rant.

“I regret the deaths. I really do. But we’re all going to die someday. There’s no use fleeing reality. We have to stop being a country of fags,” he said in a speech. “We have to face up to it and fight. I hate this faggot stuff.”

In Italy, virus restrictions were increased in five of the country’s 20 regions on Tuesday.

Hong Kong to step up Covid-19 border controls, city on alert for infection rebound

Hungary, one of the hardest-hit countries in terms of deaths in proportion to the population, has also announced new measures to come into force on Wednesday.

Elsewhere on the continent, Albania imposed a nighttime curfew and Estonian President Kersti Kaljulaid went into self-isolation after coming into contact with someone diagnosed with Covid-19.

In Greece, the government stopped supermarkets from selling “non-essential goods” in order to avoid unfair competition against smaller shops that have been forced to close, following a similar move in France.