France started vaccinating children over five and China plunged a city into a strict lockdown on Wednesday as governments scramble to contain fresh virus surges driven by the Omicron variant.
The latest clinical data suggest Omicron does not cause more severe illness than its predecessors, notably the Delta variant first identified in India, which accounts for the bulk of cases worldwide.
But scientists warn the highly transmissible strain, which South Africa first reported to the World Health Organization last month, could cause more deaths if soaring infection numbers overwhelm health systems.
Omicron's lightning global spread has led some governments to reimpose restrictions ahead of Christmas holidays or to re-evaluate their plans to halt the spread, dampening hopes the worst of the pandemic is over.
France on Wednesday opened vaccinations to children aged between five and 11 in its latest step to combat a fresh wave of cases.
Health Minister Olivier Veran said Omicron-fuelled daily Covid infections could exceed 100,000 by the end of December, according to modelling, with France recording almost 73,000 cases on Tuesday.
Finland also revealed plans to expand its vaccination programme to children aged between five and 12, a day after announcing bars must close at 9:00 pm on Christmas Eve as part of new restrictions to fight record Covid infection levels.
But in China, only 52 new reported infections were enough for authorities to impose a stringent lockdown on more than 13 million people in the northern city of Xi'an.
From midnight on Thursday, residents must stay at home except to buy necessities once every two days or in emergencies. Travel to and from Xi'an is heavily monitored by health authorities and non-essential businesses will close.
The move comes as China pursues its rigorous zero-Covid policy before next year's Winter Olympics in Beijing and is reminiscent of the world's first pandemic lockdown in the central city of Wuhan in January 2020.
Turkey on Wednesday granted emergency use approval to its first domestically developed coronavirus vaccine, Turkovac, although no data from its phase 3 trials in June have emerged.
Health adviser Ates Kara said Turkovac was "very successful" and could be "a little better" than other jabs and President Recep Tayyip Erdogan pledged to share it "with all humanity".
Turkey's announcement came after Israel on Tuesday became the first country to make fourth jabs widely available, amid fears Omicron is more resistant to existing vaccines.
Prime Minister Naftali Bennett said citizens over the age of 60 and medical teams would be eligible for a fourth Covid vaccine shot, following the recommendation of an expert panel.
"The world will follow in our footsteps," he tweeted.
Britain on Wednesday broke its own ground in fighting Covid-19 after buying millions of doses of a new treatment taken as a pill and cutting the isolation period for infected people.
Prime Minister Boris Johnson's government signed deals to acquire 4.25 million courses of Pfizer's ritonavir and US rival Merck/MSD's molnupiravir antiviral drugs.
Those catching the virus in England can now stop isolating after seven days rather than 10 if they test negative twice, potentially allowing more people to join family Christmas celebrations.
The decision came despite WHO chief Tedros Adhanom Ghebreyesus' plea to cancel New Year events because it was better to "celebrate later than to celebrate now and grieve later".
Scientists are racing to know more about the Omicron strain, with cases reported worldwide among fully vaccinated and previously infected people.
Sweden on Wednesday joined Italy and Greece in making a negative test mandatory for EU travellers seeking to enter the country -- even if they are fully vaccinated.
Omicron has already become the dominant strain in countries including Britain, Denmark and the United States, prompting US President Joe Biden on Tuesday to announce a raft of new measures.
These included shipping half a billion free home tests from January and giving $580 million (513 million euros) in additional aid to international organisations to fight Covid.
The Covid-19 pandemic has caused at least 5,368,777 deaths and 275,675,124 infections since the virus first emerged in China in December 2019, according to an AFP tally compiled from official sources at 1100 GMT on Wednesday.
© Agence France-Presse