Omicron probably in most countries, spreading at 'unprecedented speed': WHO

New Delhi : The World Health Organization (WHO) has warned that Omicron variant of coronavirus has probably reached most countries in the world and it is spreading at an 'unprecedented speed'. 

Dutch primary schools will remain closed as Europe is battling with the fresh wave of infections and hospitalizations.

Omicron was first detected in South Africa on November 24 and it was notified that it has a large number of mutations, setting the alarm bells ringing since its discovery.

Early data had shown that it can resist vaccines and it is highly transmissible, even more than the Delta variant.

WHO chief Tedros Adhanom Ghebreyesus told reporters 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".

On Monday, UK Prime Minister Boris Johnson had announced first death due to Omicron variant, but it is still maintained that the strain does not causes severe illness.

The WHO has said that South Africa has shown an increase in the number of positive cases but the number of deaths has remained low as compared to Delta variant.

It also urged nations to take proactive measures to stop the spread of infections.

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

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