The World Health Organization has warned that the Omicron variant of COVID-19 is spreading at an unprecedented rate and urged countries to act

WHO chief Tedros Adhanom Ghebreyesus told journalists that the strain had been reported in 77 countries and had probably spread to most nations undetected "at a rate we have not seen with any previous variant".

At the same time the WHO on Tuesday also gave reason for some optimism, saying Africa had recorded a massive rise in cases over the past week but the number of deaths were lower than the previous waves.

However, it urged countries to act swiftly to rein in transmission and protect their health systems and warned against complacency.

WHO expert Bruce Aylward emphasised against "jumping to a conclusion that this is a mild disease".

"We could be setting ourselves up for a very dangerous situation," he added.

Omicron, first identified by South Africa and reported to the WHO in late November, has over 30 spike proteins which has raised fears that it has the potential to break through vaccine protection.

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Early data suggests it can be resistant to vaccines and is more transmissible than the Delta variant, which was first identified in India and is now the dominant infection worldwide.

The WHO also warned that the low vaccination rates in regions such as Africa would provide breeding grounds for new variants such as Omicron.

It estimated it will take Africa until May 2022 to have 40 percent vaccination coverage and until August 2024 to reach 70 percent. There is a shortage of vaccines for poor countries while the advanced nations have stepped up their campaign to administer third doses in the wake of surging Omicron infections.

Europe now appears to be bearing the brunt of Omicron infections, accounting for as many as 62% of the world's total Covid cases in the past seven days.

Scientists have predicted the true number already infected with Omicron in Britain could be as high as 200,000 a day. The English Premier League also reported a record number of infections which is likely to lead to a disruption in the schedule for matches.

The Netherlands has followed in the footsteps of other European nations in bringing back restrictions to fight the fresh spurt in cases. The government has announced that primary schools will shut next week and a night lockdown will be extended.

The United States, the country hardest hit by the coronavirus pandemic, crossed 800,000 Covid-19 deaths on Tuesday, according to figures compiled by Johns Hopkins University showed.

Although Britain on Monday confirmed what is thought to be the world's first Omicron death, there is no proof yet that Omicron causes more severe illness.

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