Director-General of Health Dr Ashley Bloomfield says the Ministry of Health expects it will take Auckland just over a month before 90 percent of the population is fully vaccinated.
Around 70 percent of the region is fully vaccinated now, with close to 90 percent having had one dose.
"It will take the next few days to get up to 90 percent [single dose]," Dr Bloomfield told Morning Report.
"Then we've got that gap of at least three weeks. For most people at the moment, it's about three to four weeks for that second dose."
Dr Bloomfield said while 90 percent has always been the aim, it's by no means the end and there's plenty of opportunity for more people to get vaccinated.
"It's not just a figure, it's not just a target, it's a milestone, because we don't stop there, we keep going, everything, every vaccination above 90 percent, adds additional protection."
He said the Ministry of Health believes the R number for the virus is around 1.2 or 1.3 and case numbers are still going to go up.
"The best way to keep them down as low as possible is for people to keep abiding by those alert level three restrictions. That's fundamental."
Auckland's border is expected to remain in place for some time until vaccination rates improve in other parts of the country.
Bloomfield said the hard border is doing a good job at protecting vulnerable communities where the rates aren't tracking as well.
"It's largely confined the cases to Auckland, which is great, and it means we can take that ongoing elimination approach outside of Auckland.
"The Prime Minister did signal a week or two back that the intention is to keep that boundary for the time being. I think there's good rationale for that, if we can avoid the cases leaking out of Auckland as much as possible, that serves everybody."
He says the whole country needs to be at 90 percent or more for optimal protection.