The Ministry of Health is promising New Zealand has enough vaccines but says the rollout will be "tightly controlled" over the next five weeks to ensure it stays that way.
On Friday the Director-General of Health Dr Ashley Bloomfield said there is sufficient supply to deliver more than half a million vaccines over the next five weeks - but until more doses are delivered in July, stocks will be "tight".
He says District Health Boards (DHBs) will need to manage their new bookings carefully to ensure there is enough to go around - but current bookings will not be affected.
The Ministry of Health is also cracking down on walk-ins.
"Appointments will be required for vaccinations at all DHBs so we can carefully manage our supply through this period," said Bloomfield.
"Even through this more tightly controlled phase, DHBs will continue to administer more than 100,000 doses per week."
Until more vaccines are delivered, vaccinations planned for people in prison, and some defence force personnel will be "slowed but not stopped".
Bloomfield stressed despite cracking down on vaccinations, the country will have enough vaccines for everyone above the age of 16 to have two doses by the end of the year.