But the modeller said it could also be that lots of people were holding off for the Super Saturday vaccination drive.
Kiwis still want to be encouraging as many people to get vaccinated as we can and it was about connecting with those who were hard to reach, Plank said.
Auckland's vaccination rate was now 88 per cent (at least one dose) - with 67 per cent of eligible residents fully vaccinated.
Today's numbers showed 65 more people have tested positive for Covid and all were in Auckland.
There are 34 people in hospital with Covid-19 - six in intensive care (ICU) or high dependency units.
New Zealand's overall vaccination rate is 88.4 per cent (first dose at least) with 61.8 per cent of the eligible population fully vaccinated.
Of the 71 cases announced on Thursday, 30 had exposure to events in the community and the rest were isolated through their infectious period.
A pop-up testing centre has been set up in Te Awamutu after a second positive Covid wastewater detection in the town.
Public health officials have yet to identify anyone who returned to the area from managed isolation and quarantine and could be shedding the virus in the area.
For this reason, anyone in the Te Awamutu area who has symptoms of Covid, or any household members who are symptomatic, or anyone who travels in and out of the area regularly for work, is urged to get tested as soon as possible.