Europe scrambled Thursday to regain control over a resurgent coronavirus as governments urged adult boosters and jabs for young children in a sign of growing unease over a pandemic that has killed 1.5 million people on the continent.

Berlin, Paris and Lisbon were among capitals weighing tighter Covid restrictions and broader vaccination campaigns as surging cases and the encroaching winter threaten to undo hard-won gains against the virus over the summer.

In the Czech Republic, President Milos Zeman returned to hospital just hours after being released to name a new prime minister as he tested positive for Covid-19.

With governments already struggling to cope with the more infectious Delta variant, the discovery of a new and troubling strain in South Africa was a stark reminder that the fight against Covid-19 is far from won.

Germany weathered earlier bouts of the pandemic better than many other European countries, but has seen a recent resurgence
Germany weathered earlier bouts of the pandemic better than many other European countries, but has seen a recent resurgence AFP / Christof STACHE

Britain, in response to the new variant, said Thursday it would ban travel from six southern African countries: South Africa, Namibia, Lesotho, Eswatini, Zimbabwe and Botswana.

British Health Secretary Sajid Javid said scientists were "deeply concerned" about the new variant as it "may be more transmissible" than Delta and current vaccines less effective against it.

In Germany, outgoing Chancellor Angela Merkel urged more stringent controls. France stepped up booster shots, and the European Union's medicines agency gave the green light to a vaccine for five-year-olds.

Even countries with relatively high rates of vaccination are now tightening Covid-19 measures that had only recently been relaxed.

Incoming chancellor Olaf Scholz has voiced support for compulsory vaccinations for health staff
Incoming chancellor Olaf Scholz has voiced support for compulsory vaccinations for health staff AFP / Tobias SCHWARZ

Merkel implored the new government succeeding her to take quick, decisive measures as the country reported a record 351 Covid fatalities in the past 24 hours, taking the official death toll since the start of the pandemic past 100,000.

Warning that "every day counts", Merkel urged her successor government for "more contact restrictions".

Germany's Covid-19 crisis has in part been blamed on its relatively low vaccination rate of about 69 percent
Germany's Covid-19 crisis has in part been blamed on its relatively low vaccination rate of about 69 percent AFP / John MACDOUGALL

Germany has had to call on hospitals elsewhere in the EU for help as some clinics face overload.

The country last week began requiring people to prove they are vaccinated, have recovered from Covid-19 or recently tested negative before they can travel on public transport or enter workplaces.

Several of the worst-hit areas have cancelled Christmas markets and barred the unvaccinated from bars, gyms and leisure facilities.

Germany's Covid-19 crisis has in part been blamed on its relatively low vaccination rate of about 69 percent, compared to other Western European countries such as France, where it is 75 percent -- even though new cases hit a seven-month high on Wednesday.

Incoming chancellor Olaf Scholz has voiced support for compulsory vaccinations for health staff
Incoming chancellor Olaf Scholz has voiced support for compulsory vaccinations for health staff AFP / Tobias SCHWARZ

A German campaign for booster shots has been marred by supply and logistics snags.

In Paris, Health Minister Olivier Veran said Covid-19 booster shots would be accessible to all adults starting this weekend.

From January 15, people over 18 would need to show proof of a top-up vaccine dose to maintain a valid Covid pass, which is required to enter restaurants, bars, gyms and other public venues.

Adding pressure, the EU Commission recommended that the bloc's vaccination certificate should become invalid once the holder's latest dose is more than nine months old.

Elsewhere in Europe, the streets of the Slovak capital Bratislava were deserted as a new partial Covid lockdown came into effect.

Even Portugal, which has an 86-percent vaccination rate, said it would impose work from home in the New Year and close bars and discotheques.

Belgium, which reimposed tougher curbs only last week, has seen an uptick far worse than projected, Prime Minister Alexander De Croo said.

The Czech government earlier Thursday implemented a 30-day state of emergency, which includes closing Christmas markets as well as nightclubs.

Hospitals in the east of the country are reaching capacity, and some have begun moving patients across the country by helicopters and ambulances.

The spiking cases see Europe re-emerge as the pandemic's epicentre, with the continent battling sluggish vaccine uptake in some nations, the highly contagious Delta variant, colder weather sending people indoors and the easing of restrictions.

An AFP tally of official figures showed Thursday that more than 1.5 million people have died from Covid-19 in Europe.

Scientists in South Africa said the new variant they discovered has multiple mutations, blaming it for a surge in infection numbers.

The number of daily infections in Africa's hardest-hit country has increased tenfold since the start of the month.

Back in Europe, the European Medicines Agency approved the Pfizer/BioNTech jab for five- to 11-year-olds, clearing the way for vaccinations in an age group where the virus is rapidly spreading and bringing the EU into line with the United States, Israel and Canada.