Major study proves vaccination-autism link a myth
Anti-immunisation campaigners are continuing to peddle misinformation despite the results of a comprehensive international review that found no evidence of a link between vaccination and autism.
The organisers of a Sunshine Coast health expo have been heavily criticised for inviting the founder of the Australian Vaccination-skeptics Network (AVN), Meryl Dorey, to speak at their event, particularly given the widespread alarm the group has caused by spreading falsehoods about the safety of vaccines.
The NSW Health Care Complaints Commission has issued a public warning following an investigation into claims made by the AVN.
In a statement released on 30 April, the Commission reported that the AVN “does not provide reliable information in relation to certain vaccines and vaccination more generally. The Commission considers that AVN’s dissemination of misleading, misrepresented and incorrect information about vaccination engenders fear and alarm and is likely to detrimentally affect the clinical management or care of its readers”.
The warning came as Sydney University researchers release the findings of a study into claims made by many anti-vaccination campaigners that immunisation is linked to autism.
The systematic international review found that there was no evidence of a link between childhood vaccinations and the development of autism or autism spectrum disorders (ASDs).
The research, based on examination of five cohort studies involving more than 1.25 million children and five case-controlled studies involving more than 9920 children, found there was no statistical data to support a relationship between childhood vaccination for the commonly-used vaccines for measles, mumps, rubella, diphtheria, tetanus and whooping cough, and the development of autism or ASDs.
Senior author Professor Guy Eslick from the Sydney Medical School said these vaccines were those most commonly cited by anti-vaccination groups as posing an autism risk.
Professor Eslick said that, until now, there had never been a quantitative data analysis of any relationship between autism, ASDs and vaccination.
“Our review is the first to do so, and we found no statistical evidence to support this idea,” he said.
Professor Eslick said the finding was significant because of the reluctance of a small but significant proportion of parents to vaccinate their children because of fears it can lead to autism.
Concerns of a link between vaccination and autism spring from a study, since discredited, published in The Lancet in 1998, that claimed to have established such an association,
The National Health Performance Authority’s Health Communities: Immunisation rates for children in 2012-13 report showed around 75,000 children five years or younger were not fully immunised last financial year, and in pockets of the population immunisation rates were well below the level required to achieve herd immunity. In particular, in North Coast NSW among one- and two-year-olds and Eastern Sydney for five-year-olds, at 86.1 per cent, 89 per cent and 86.2 per cent respectively.
Significantly, about 15,000 of these children had parents who had lodged conscientious objections to vaccination.
The results echo Council of Australian Governments Reform Council figures showing worrying gaps in immunisation in some areas that threaten to undermine protection against infection. According to the Council, in parts of NSW vaccination rates among children aged between 12 and 15 months have slipped as low as 81.1 per cent, while in South Australia, just 77.1 per cent of Indigenous children in the same age group are fully immunised.
Professor Eslick said this was particularly concerning because of serious outbreaks of measles, whooping cough and other vaccine-preventable diseases both within Australia and abroad.
“The increase in parents deciding not to vaccinate their children has substantially decreased herd immunity, increasing the risk of catching potentially more serious infectious diseases,” he said. “The risks incurred by not immunising a child is increasing substantially.”
Professor Eslick’s research was published in the journal Vaccine.
Published: 10 Jun 2014