Public figures such as Kiwi celebrity Jemaine Clement should seek the facts before sharing their opinions on the vaccine debate, an immunisation expert says.
Clement, best known as one of the Flight of the Concords duo, has posted messages on his Twitter feed backing Hollywood star Jim Carry's anti-vaccination comments.
Carey's own Twitter ravings to his millions of followers criticised the danger of immunisation, saying jabs poison children with mercury and aluminium.
In a series of tweets, Clement defended Carry's right to make such observations, saying: "well I guess anti anti vaxxers are important too! My argument is about not closing down debate."
But this has earned the oprobrium of Dr Nikki Turner, director of the immunisation advisory centre at the University of Auckland.
She said public figures had a lot of influence through their words and they should undertake some basic investigation before taking stances.
For example, in New Zealand, vaccinations no longer contained thiomersal, a neurotoxin Carry said he was against.
"It's always important to raise an issue, absolutely, but to come up with a whole lot of nonsense without even checking what you are saying, it's difficult to even know how to respond to," Dr Turner said.
"Let's have some informed debate and let's at least ask the questions. People like this are in prominent public positions because they are actors. I think they have some responsibility to at least put a little bit of thought into their statements...
"When somebody makes a statement, even if there's nothing behind it, the mud sticks. The classic example is a lot of people still believe the MMR vacine causes autism."
Dr Turner said that wasn't true but because people had made such an assertion, it was "hard to un-believe".