Those who contract Covid-19 despite being fully vaccinated are likely to require shorter periods in isolation, Director-General of Health Dr Ashley Bloomfield says.
Bloomfield told RNZ that vaccinated people appeared to be infectious for a shorter period of time.
"They're less likely to pass on the virus and if they are infectious, they are infectious for a shorter period so therefore, especially if they're asymptomatic ... they would only require a shorter period at home."
By contrast, those who are unvaccinated - even if they didn't have symptoms - were more likely to pass on the virus, Bloomfield said.
"So they would need to remain isolated to avoid passing it on to others, for a longer period."
There were 71 new community cases of Covid-19 reported on Thursday, all in Auckland.
Recent days have seen the number of unlinked cases increase markedly and Bloomfield acknowledged ICU nurses and specialists were concerned about the strain Covid-19 cases could put on ICU capacity.
"I think they are concerned about the ICUs getting full of people with serious Covid, which then rules out of course them being able to provide care for people with many other conditions."
Ensuring ICUs and hospitals didn't get overwhelmed was a "key part" of his team's pandemic response, Bloomfield said.
Keeping alert level restrictions in place, actively "chasing cases", isolating contacts, testing widely and "vaccinating furiously" remained the mainstays of the health response, he said.
"The best way to protect our hospitals and our ICUs is to get vaccinated. There's a huge difference in whether people need hospital or ICU care if they're vaccinated."
Since the start of the Delta outbreak in Auckland there have been around 170 hospitalisations, of which just three people were fully vaccinated, Bloomfield said.
"[The vaccine] is highly protective."
He added that around four per cent of the outbreak's total case numbers were fully vaccinated but the "vast majority" of cases hadn't had one vaccine.
"We know that if people are vaccinated, most of them don't even get symptomatic illness."