The Omicron variant of Covid-19 is dangerous -- and especially so for those who have not been vaccinated against the disease, the World Health Organization warned Wednesday.
The WHO said the global surge in cases was being driven by Omicron, which is more transmissible than the previously dominant Delta variant.
More than 15 million cases were reported to the WHO last week -- with millions more cases thought to have gone unrecorded.
But the UN health agency insisted there should be no surrender to the variant, dismissing the notion that it could be a welcome conduit to ending the pandemic.
"While Omicron causes less severe disease than Delta, it remains a dangerous virus -- particularly for those who are unvaccinated," WHO chief Tedros Adhanom Ghebreyesus told a press conference.
"We mustn't allow this virus a free ride or wave the white flag, especially when so many people around the world remain unvaccinated."
The "overwhelming majority" of people admitted to hospitals are unjabbed, he added.
While vaccines remain very effective at preventing death and severe Covid-19 disease, they do not fully prevent transmission, said Tedros.
"More transmission means more hospitalisations, more deaths, more people off work -- including teachers and health workers -- and more risk of another variant emerging that is even more transmissible and more deadly than Omicron."
Tedros said that the numbers of deaths worldwide had stabilised at around 50,000 per week.
"Learning to live with this virus does not mean we can, or should, accept this number of deaths," he said.