Experts are warning that more children could die of preventable illnesses unless parents receive greater encouragement to vaccinate them.
A study of almost 7000 women and 4000 of their partners has found that during pregnancy, just 39% received information encouraging them to vaccinate their newborns.
47% received no information either way, while 14% received information discouraging them from vaccinating.
“It’s disturbing that in this project we found some health professionals were providing a discouraging message”, Dr Cameron Grant from the University of Auckland told ONE News.
Mothers-to-be who received discouraging information were twice as likely not to have their children immunised, exposing them to deadly diseases like whooping cough. Three babies died in New Zealand during the last whooping cough outbreak.
Dr Grant told TVNZ's Breakfast it was a "great concern" that negative messages were having a bigger impact on parents.
"Those were from a variety of sources - antenatal classes, lead maternity carers, GPs, a whole range," said Dr Grant, who is Growing Up in New Zealand associate director and Starship paediatrician.
"I worry that people don't see the pregnancy time period as the most important period to be getting really good information about immunisation.
"You don't want to wait until baby's born. Parent's aren't getting any sleep, they haven't got time to decide - they've got to have it all sorted out before baby's born."
Roughly 93% of Kiwi kids are being vaccinated in time, but Dr Grant believes more can be done to promote the benefits of vaccination, make it more accessible to families without access to a doctor, and dispel common myths - such as vaccination can lead to autism in children.
“I just worry a little bit that maybe we’re not selling the encouraging message as well as we could”, he said.
Prof Grant reiterated that there was no link between immunisation and autism.
"Unfortunately vaccination is always something that gets linked with other things. You're giving a vaccine to someone who is well so it's always something that makes people feel a little bit nervous."
"I think people sometimes feel they got perhaps more ability to protect themselves from these infections than they really have. They are such infectious diseases.