The EU's disease control agency on Friday joined frantic health workers across Europe in sounding the alarm about the surge in coronavirus infections as the World Health Organization warned of an "exponential" rise in cases.

Several countries in Europe are reporting infection rates higher than during the first wave of the pandemic in March and April.

Spain's "real number" of infections is more than three million, Prime Minister Pedro Sanchez said Friday, just two days after the country officially became the first European Union country to pass a million cases.

Several regional authorities have announced new measures, with the Madrid region banning household gatherings from midnight to 6 am and halving capacity in bars and restaurants.

France announced on Friday that it had topped a million registered cases.

On the other side of the Atlantic, US presidential hopeful Joe Biden said that, if elected, he would mandate coronavirus vaccines be free for all Americans, part of a national strategy to "get ahead of this virus".

"Once we have a safe and effective vaccine, it has to be free to everyone -- whether or not you're insured," Biden said in a speech laying out his pandemic response plan just 11 days before election day.

One week of new COVID-19 cases. Infographic: AFP

The clinical trial for a COVID-19 vaccine being developed by AstraZeneca and Britain's University of Oxford has resumed in the United States, the drugmaker said Friday.

The US was the only country where the trial remained suspended following a participant's illness six weeks ago.

The WHO said the northern hemisphere was facing a crucial moment in fighting the pandemic.

"Too many countries are seeing an exponential increase in COVID-19 cases and that is now leading to hospitals and intensive care units running close to or above capacity -- and we're still only in October," WHO chief Tedros Adhanom Ghebreyesus told a virtual press conference.

Across the planet, COVID-19 has now claimed the lives of 1.1 million people -- about one fifth in the United States -- and infected close to 42 million.

Across Europe, governments are slapping urgent new restrictions on daily life, with France extending a curfew to cover 46 million people and Ireland locked down again.

"The continuing increases in COVID-19 infections... pose a major threat to public health, with most countries having a highly concerning epidemiological situation," said Andrea Ammon, director of the European Centre for Disease Prevention and Control (ECDC).

The agency said all EU countries except Cyprus, Estonia, Finland and Greece fell into a "serious concern" category, as did the United Kingdom, up from just seven a month ago.

Brussels and Wallonia, the French-speaking region of which Liege is a major city, are now the epicentres of Europe's renewed crisis

"We're losing. We're overwhelmed. We're bitter," said Benoit Misset, head of the intensive care unit at the University Hospital in the Belgian city of Liege, where several of his staff are having to work despite being COVID-positive -- if asymptomatic -- themselves.

"It's trench warfare", with the difference that "it's not bombs, it's a virus" and "it's the virus calling the shots, not us, not politicians, not scientists," Misset told AFP.

In France, the boss of Paris public hospital group AP-HP warned the second wave could be worse than the first as the government expanded a nighttime curfew to cover more than two-thirds of the population.

"There are many positive people, infectious, in the streets without knowing it and without anyone else knowing it," Martin Hirsch told French radio.

Wales was set to enter a full lockdown on Friday evening, a day after Ireland shut down.

Poland meanwhile adopted a nationwide "red zone" lockdown that includes the partial closure of primary schools and restaurants.

Only Sweden, which famously refused to lock down earlier this year, continued to stick to its guns despite a rise in cases.

Infection control measures have drawn the ire of many struggling to keep their businesses or jobs from going under in the pandemic-induced economic downturn.

As such, the Czech Republic was up in arms after Health Minister Roman Prymula was caught -- maskless -- leaving a restaurant that should have been closed under his own restrictions.

He insists he was having a meeting in premises adjacent to the restaurant.

As the pandemic lingers, governments have been forced to dive in and help businesses being buffeted by a constant seesaw of lockdowns and reopenings.

Struggling Scandinavian airline SAS said Sweden and Denmark agreed to increase their stakes to try to help it weather the crisis.

And the Eiffel Tower in Paris -- one of the world's most visited sites -- is experiencing a collapse in visitor numbers, with ticket sales down 80 percent.

But bucking the trend, British retail sales climbed in September for the fifth month in a row.

And US fast-food chain Kentucky Fried Chicken said it would create 5,400 jobs in Britain and Ireland on strong takeaway demand.