The first case of the Omicron Covid-19 variant has been found in New Zealand.

The case is in managed isolation in Christchurch, Stuff understands.

Omicron case numbers are surging overseas. Britain recorded nearly 79,000 new Covid-19 infections in a single day amid warnings that the country would continue to 'break records” in the weeks ahead.

The Omicron variant appears to cause less severe disease than previous versions of coronavirus. The Pfizer vaccine seems to offer less defence against infection, but does offer good protection from hospitalisation, according to an analysis of data from South Africa, where the new variant is driving a surge in infections.

While the findings are preliminary and have not been peer-reviewed, they line up with other early data about Omicron's behaviour, including that it seems to be more easily transmitted.

On Monday, Prime Minister Jacinda Ardern indicated the start date for letting returnees skip managed isolation and quarantine (MIQ) may be in jeopardy due to the Omicron variant.

Fully vaccinated New Zealand citizens and residents returning from Australia are supposed to be able to bypass MIQ and self-isolate for seven days starting from January 17, the Government announced last month.

Those returning from other countries would be able to do the same from February 14, while the border would begin to open to all fully vaccinated arrivals – not just citizens or residents – from April 30.

• STUFF