Pro-vaxxer's child threatened by anti-vaxxers

A row between a Northland doctor and the anti-vaccination movement has turned nasty.

Dr Lance O'Sullivan had stormed the stage at the screening of the Vaxxed documentary in Kaitaia and was later caught on video in a heated exchanged with movie organiser Tricia Cheel.

He says he's been subject to personal attacks targeting his disabled son and in return, he's described his critics as "vile" and "low lifes".

"One of them even went so far as to start making comments about my son, who has a serious, serious medical condition, and making light of that in the context of vaccinations," he told Newshub.

But his bigger worry is that parents will be put off vaccinating their children.

"My great concern is we've seen immunisation rates affected by this campaign."

Dr Nikki Turner from the Immunisation Advisory Centre says MMR rates are currently at 95 percent for the first dose.

"New Zealand is very close to eliminating measles, what we are relying on is New Zealand to maintain high rates of immunisation coverage and then we will not see measles in the New Zealand community," she told Newshub.

The film has been shown in eight locations around the country and promoter WavesNZ says people should be allowed to make up their own minds.