Northland doctor Lance O'Sullivan is a conscientious public health campaigner
Who is Dr Lance O'Sullivan?
He's the renowned Northland medical practitioner who stormed the stage at a screening of the movie Vaxxed, which peddles widely debunked claims linking autism to vaccinations for measles, mumps, and rubella.
It's not the first time O'Sullivan has taken a stand, but his stage invasion in Kaitaia and impassioned plea against sham "science" has struck a nerve.
He won the New Zealander of the year accolade in 2014 and has made headlines before for his work in rural health.
* Doctor leaps on stage to vent against anti-vaccination
* Northland GP named New Zealander of the Year
* Anti-vaccination film Vaxxed spreading 'myths'
* Controversial anti-vaccination film Vaxxed
* Why Lance O'Sullivan really is a good doctor
At a screening on Monday, O'Sullivan leapt on to the stage to vent his anger at the anti-vaccination movement.
"I come here with a lot of anger ... and that's because I am adamantly opposed to this because this position, this idea of anti-immunisation has killed children around the world and actually will continue to kill children ... whose parents are put off immunisation because of misinformation - misinformation based on lies, quite frankly."
The science is clear: vaccines for measles, mumps and rubella do not cause autism but the anti-vaxxer movement has grown in influence, leading to cases in which vaccine-preventable diseases have returned at rates not seen in decades.
Study after study has not found any credible evidence of any link between autism and MMR.
O'Sullivan, who practises in Kaitaia, was born in Auckland - the son of a meat worker - and is known for his philanthropy, public health advocacy, and his outreach work for rural patients, Pacific and Maori health.
He and wife, Tracy, set up a low cost clinic to foster better access to basic health care for people in the far north and he set up the Moko Foundation, a school-based health service.
When he was named New Zealander of the Year, he said he was a proud husband, brother, father, and mate.
"New Zealand has given me so much. On behalf of everyone here tonight, I would like to confirm my commitment to continuing to make New Zealand a great place for us all."
He told Stuff child poverty was a big focus.
"I'm most proud of taking what I feel and turning it into action around the things I saw that weren't so good for the communities I live and work in.
"Rather than just talking about it, [I'm] doing something."
In 2013, he was pipped as an emerging leader by the Sir Peter Blake Trust.
He's been named as a champion of public health by the Public Health Association and Maori of the Year.
O'Sullivan is also an author, a public speaker, and public health advocate.