A new study has found parents researching childhood vaccinations online are likely to encounter significant levels of misinformation.
While 20 percent of websites identified by Google searches and 25 percent of videos published on YouTube were negative about vaccines, that figure jumps to 50 percent of pages on Facebook.
The study's lead researcher, Dr Lucy Elkin from the University of Otago, told Morning Report that Facebook's lax censorship could be the reason for higher figures on the platform.
"I think they are beginning to do some work in this area ... the amount of negative information on vaccines has decreased over time. Since I did my research, YouTube and Google have been actively censoring some of their information - Facebook less so.
"I think what actually needs to be happening is those that are pro-vaccine need to be stepping it up and putting more information out there in support of vaccinations."
The negative messages tend to express a distrust of government, public health, and particularly pharmaceutical companies.
"There's a lot of questioning of the motives of pharmaceutical companies as to why they're producing these vaccines and a lot of mistrust that the vaccines can be harmful and they're hiding information from the wider public.
"We all know the common myths about vaccinations, such as they can cause autism, those myths are still out there and being perpetuated."