There are 56 new cases of Covid-19 in the community today, the Ministry of Health has confirmed.
In a statement, the Ministry said there were 48 people with the coronavirus in hospital, including seven in ICU.
Earlier today, Covid-19 modeller Dr Dion O'Neale from the research institute, Te Punaha Matatini, said it was unlikely case numbers would explode immediately now Auckland's border was open, saying a gradual spread was more likely.
But he expected the new Omicron variant to spread much faster than Delta.
Director of Public Health Dr Caroline McElnay said Omicron was a game changer as it "spreads fast ... cases get infected very quickly after exposure".
That made rapid tracing of contacts all the more vital, to get them isolating before they could expose anyone else.
The ministry was looking particularly closely at New South Wales were Omicron cases were soaring, McElnay said.