New Zealand is experiencing its highest peak in Covid-19 cases since December 2022, Professor Michael Baker says.
Last week, the ministry reported 6146 new cases of the virus and 19 further deaths.
That was a substantial increase on the number of cases reported the previous week - which stood at 3922.
The data came from wastewater testing, Baker said, but hospitalisations were also up.
"We're up to about 35 people a day going to hospital with this infection," he said.
Baker told RNZ's First Up one in three people are still contagious five days after testing positive for the virus.
Despite the recommended isolation period now only being five days, Baker suggested people still getting a positive Covid-19 test wait to test again on day 6 or 7 before going back into society.
"The biology hasn't changed," Baker said, but there was more pressure for people to go back to work and school.
Baker said he would like to see money in this week's Budget going towards the Covid-19 response.
It was important for health and productivity that the government continued to fund booster shots, RAT tests and the anti-viral medication.
As soon as people had to pay for these, low income households would miss out.
Baker said it had to remain fair and equity had to be maintained.
Prioritising booster shots was also important, Baker said.
People over the age of 30 were eligible for a booster every six months.
And while it would not stop someone from becoming infected with Covid-19 and potentially passing it on, the immunisation activated parts of a person's immune system that could help stop them getting seriously ill.
Baker also encouraged mask wearing - especially N95s - that have a good seal around the mouth and nose.
A recent study Baker took part in proved face masks really did help reduce the spread of respiratory infections.
