Kiwis still unsure about getting the Covid-19 vaccine might be best reached by health advocates through their favoured avenue for information - social media.
A new analysis also suggests those outright against receiving a shot could be perhaps swayed through friends, family members or local community leaders.
New Zealand has just launched its largest-ever vaccination campaign, accompanied by a major awareness and education effort to encourage uptake.
Director general of health Dr Ashley Bloomfield has indicated a vaccination target of 70 per cent of the population, which experts say would be at the lower end of the threshold to achieve herd immunity against the virus.
In his study, Massey University communications lecturer Dr Jagadish Thaker drew on more than 1000 survey responses that were collected last year.
The data showed about a third of Kiwis were either "hesitant" over (24 per cent) or opposed to (12 per cent) vaccinations - in line with more recent Government surveys.
Those merely sitting on the fence were more likely to be 18- to 25-year-olds or 36- to 45-year-olds, and to have low to moderate levels of education and lower incomes.
They were also slightly more likely to be female and were also more likely to be Māori, compared with other ethnicities.
Nearly 80 per cent indicated being "neutral" over getting the vaccine - and were more likely to have high trust in social media as a source of information, but less likely to trust mass media, scientists, and family and friends.
Thaker noted that, with Covid-19 specifically, they were more likely to rely on social media for a source - and less likely to believe that false information on their timelines was fake.
"That's a double-edged sword, because while they see more information, and trust it, we don't know if it's authentic, and not linked to some kind of conspiracy," he said.
"But this suggests that, rather than reaching them through traditional mass media, health experts might be more effective in social media-based campaigns."
Health advocates were likely to have a tougher time swaying "sceptics" on the evidence and efficacy behind the vaccines.
While their demographic profile was similar to "hesitant" people, they were more likely to be of a more advanced age - or 46 years and older.
About 99 per cent said "no" to getting the vaccine, with around two in 10 reporting they'd previously refused vaccinations for their children.
Like the vaccine hesitant, they had less trust in media and scientists - yet they also had little trust in social media, instead relying on family and friends for information.
"So health experts giving out more information to them might not work out so well," Thaker said.
"What we've suggested are more localised campaigns, using opinion leaders in their communities, rather than mass media or expert-driven ones."
Thaker pointed to another concerning point that came out of his analysis.
"Levels of hesitancy appear to be increasing when they should be decreasing, given the vaccines are being administered in lots of countries, and go through our own testing process here," he said.
"There's all kinds of news about now, and it seems that just watching some of it, or seeing some of it on social media, can have an effect on them."
Elsewhere in the analysis, those most enthusiastic about the vaccines were more likely to older, highly educated and have higher incomes, with more trust in science and the media than social media or family and friends.
About 98 per cent of this group - accounting for 36 per cent of respondents - said they'd get vaccinated when they could.
The fourth group - those in general support of being vaccinated and making up about 28 per cent - were typically aged 18 to 45, with some tertiary education, and had middle to high incomes.
About 95 per cent answered "yes" to taking a vaccine and had high trust in mass media and scientists.
While also they trusted social media, they were more likely to report any fake news they saw.
Ultimately, Thaker felt it was important to reassure those already in support of vaccinations about the evidence behind them - but nonetheless believed the focus should be on hesitant people.
Immunisation Advisory Centre director Dr Nikki Turner agreed "tailored" messages were needed for different groups - and this had been done in previous vaccination campaigns.
"It's about asking, what are people's concerns, have they been listened to, and are they being responded to in the right way, with people they trust?"
She acknowledged the unfiltered environment of social media - which could often amplify misinformation back to people - remained a challenge, and something the world was still grappling with.
Still, Turner cautioned against vilifying those opposed to vaccines.
"Often, they'll have very sensible or rational reasons behind their decision-making, and we certainly won't shift that by demonising them," she said.
"But if we can trust each other enough to have a conversation, that's the beginning of moving through their issues."