There's concern current Level 3 restrictions in Auckland and parts of Waikato aren't enough to keep the Covid-19 Delta outbreak from growing as new cases continued to climb through Labour weekend.
109 new Covid-19 community cases were recorded in New Zealand on Monday - the second-highest daily tally since the pandemic began.
Of Monday's cases 103 were in Auckland, four in Waikato and two in Northland.
Microbiologist Dr Siouxsie Wiles fears Delta cases in Waikato indicates that current Level 3 restrictions in parts of the region won't be strong enough to prevent the virus running rampant.
"I'm not going to sugar coat it, the outbreak is growing and it's really clear that Level 3 is not enough to contain Delta and we're seeing that in the Waikato," she told Breakfast.
There are now 87 cases of the virus in Waikato. The north Waikato town Tuakau reported its first Covid-19 on Monday, joining Hamilton, Te Awamutu, Kihikihi, Raglan and Ōtorohanga as locations with cases.
Wiles warned that responding quickly to the current outbreak with public health measures is vital to preventing case numbers exploding.
"What we also have to be very wary of is the fact that once cases start to go exponential, they can increase very, very quickly," she said.
"They can quite quickly overwhelm health systems and you have to act before that happens so sometimes it can look like you're acting too soon but actually you're acting just in time."
Wiles added that getting vaccinated is a significant tool in curbing the outbreak, with the vast majority of people contracting the virus and being hospitalised with it being unvaccinated.
"As we're seeing around the world, this is becoming a pandemic of the unvaccinated."
While she agrees with the Government's 90 per cent vaccination goal, Wiles says people need to look after those most vulnerable who can't get the jab.
"We do need to be patient, I know this is really hard for everybody, we've all had enough of it but the virus doesn't care about that.
"If our hospitals become overwhelmed it's not just people with Covid who suffer it's everybody... we need to protect everybody."