Explainer - All New Zealanders aged 16 and over can book their first dose from 1 September, and second doses will by default be six weeks later, the government has announced.
What do the changes mean and will people need to rebook their vaccination?
RNZ is here to clear it all up.
New dates of eligibility for different age groups
The government had promised that every eligible person in New Zealand would have had the chance to get the vaccine by the end of the year.
Now, with plans for a risk-based border system depending on the vaccine rollout, the government is bringing forward the dates people will be able to book their first dose.
This will include a shift in focus to prioritise giving more people their first dose, over fully innoculating a smaller percentage of the population.
Director-General of Health Dr Ashley Bloomfield said the earlier dates were because of the high level of interest and increased system capacity.
"We are progressing well with our roll-out plan and are on track to make the vaccine available to everyone in New Zealand aged over 16 by the end of the year," he said.
Six weeks between doses: Re-bookings optional
The minimum gap between first and second doses will also increase to six weeks, up from three.
Bloomfield said the gap extension would take effect from today.
"Moving to a longer gap allows us to give a first dose to a larger number of people faster, which means providing more people with partial protection sooner," he said.
"Early findings from a small number of well-designed studies show that an extended duration between doses of the Pfizer vaccine gives at least an equally robust immune response, with no additional safety concerns."
People who had already booked their vaccines would not be required to rebook, but could choose to if they wished.
"People who already have vaccinations booked less than six weeks apart can keep their second appointment or choose to change it. Either way, the most important thing is that everybody needs two doses of the vaccine to be fully vaccinated. "
Those who already had two doses would still have very strong protection, he said.
Those expecting to get their inoculation through their GP, pharmacy or primary care provider could contact them to reschedule, while all others could go to bookmyvaccine.co.nz, or the Covid-19 vaccination healthline on 0800 28 29 26.
Bloomfield said people at higher risk - like those who have compromised immune systems or working in high-risk settings - may be advised to get their doses three weeks apart.
Some other situations may require faster second doses.
"For example, someone travelling overseas may require their doses sooner than six weeks."