Austria will become the first country in western Europe to reimpose a full COVID-19 lockdown, it said on Friday as neighbouring Germany warned it may follow suit, sending shivers through financial markets worried about the economic fallout.

A fourth wave of infections has plunged Germany, Europe's largest economy, into a national emergency, Health Minister Jens Spahn said. He urged people to reduce their social contacts, warning that vaccinations alone would not reduce case numbers.

Roughly two-thirds of Austria's population is fully vaccinated against COVID-19, one of the lowest rates in western Europe. Its infections are among the highest on the continent, with a seven-day incidence of 991 per 100,000 people.

"We have not succeeded in convincing enough people to get vaccinated," Chancellor Alexander Schallenberg told a news conference, saying the lockdown would start on Monday and the requirement to be vaccinated on Feb. 1.

"It hurts that such measures still have to be taken."

Asked if Germany could rule out an Austrian-style full lockdown, Spahn said: "We are now in a situation - even if this produces a news alert - where we can't rule anything out.

"We are in a national emergency," he told a news conference.

European stocks retreated from record highs, while government bond yields, oil prices and the euro tumbled as the spectre of a fresh COVID-linked lockdown in Germany and other parts of Europe cast a fresh shadow over the global economy.

As cases rises again across Europe, a number of governments have started to reimpose limits on activity, ranging from Austria's full lockdown, to a partial lockdown in the Netherlands, to restrictions on the unvaccinated in parts of Germany, the Czech Republic and Slovakia.