Unvaccinated Kiwis will now wait six weeks between their first and second Covid vaccine doses.
The decision comes alongside an acceleration of the Government's age-band eligibility system, which will allow anyone over 16 years old to book a vaccination appointment from September 1.
Director general of health Dr Ashley Bloomfield said the three-week gap between vaccines that almost 850,000 fully vaccinated Kiwis experienced would be doubled to ensure further protection against threatening variants.
"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.