People are changing their appointment to extend the time between doses of the Pfizer vaccine, says the medical director of the College of General Practitioners.
The government is currently examining the case for changing the recommended three-week gap between the two doses to eight weeks.
Dr Bryan Betty told Morning Report three weeks between doses is adequate.
"But what's emerged overseas, that if you extend the gap to between six and 10 weeks there may be an enhanced immune response.
"As we've seen with Covid as time goes on and the evidence emerges, things change and this is one of those points I think we're at where we could have an extended gap between the two vaccinations."
Anecdotally, people are already changing their appointments, he said.
But, he said, a change in recommended time between doses doesn't mean appointments would need to be rescheduled.
"It's always been the case that three weeks was the minimum for the gap to get an immune response, that if people went over there wasn't a due concern over that."
He said it would be an advantage for the system as there would be more space for people to get their first dose.
It would also provide a reassurance that you would still get an immune response with a gap over six weeks, he said.
"At the moment we don't have Covid in the country, I agree with Professor (David) Skeggs that there is always a likelihood that we would have an outbreak before the end of the year within New Zealand, therefore we need to get on with it."
Professor Michael Baker told Morning Report the research is fairly convincing that delaying the second injection increases the immune response.
New Zealand has the advantage of being able to do so, he said.
"Because we don't have at this stage circulating virus, we don't have that incredible urgency to get two doses in to everyone as fast as possible. We can delay that second dose.
"You certainly get a lot more antibodies generated if you delay that second dose and they are associated with better protection."
He said the big unknown with all the vaccines of course is how long that protection lasts.
It's entirely understandable given the amount of time we have been dealing with the virus and how long we've had vaccines for it, he said.
"But it's a reasonable idea that if you delayed its second dose maybe eight weeks, maybe a little longer, that you will have better long-term protection."
Betty said we need to vaccinate people as quickly as possible.
"The more people that start the programme, the better."
He expects the government to make an announcement about changing its recommendation in coming weeks.