Anti-vaccination advocates may be appearing more often in your Facebook feed, but the data shows a very different story. Surprisingly, the overall level of vaccination objection (registered and unregistered) has remained largely unchanged since 2001.
Dr Frank Beard and colleagues from the National Centre for Immunisation Research and Surveillance at The Children's Hospital at Westmead and the University of Sydney examined the trends in registered vaccination objection and estimated the contribution of unregistered objection to incomplete vaccination among children in Australia.
They found that registered vaccination objection affecting children aged one to six years had increased from 1.1 per cent in 2002 to 2.0 per cent in 2013. However, in this period the proportion of children who were incompletely vaccinated, but for whom no objection was recorded, declined.
"Most areas with high levels of recorded objection were in regional zones, with marked clustering in northern New South Wales and south-east Queensland," the research states.
Further, more than half (52 per cent) of the 2.4 per cent of children with no vaccinations and no recorded objection were born overseas. The authors suggest, however, that most are likely to have been vaccinated, but this had not been recorded on the Australian Childhood Immunisation Register (ACIR).
"We recommend that primary care clinicians pay close attention to ensuring that the vaccination history of overseas-born children is correctly recorded in the ACIR," Beard urged.
Extrapolating their data, the authors estimated that 1.3 per cent of children were incompletely vaccinated because of unregistered parental vaccination objection, so that an estimated total of 3.3 per cent of children in Australia aged one to six years were affected by a registered or unregistered objection.
As a 2001 survey had found that 2.5 to 3.0 per cent of children were affected by parents who had registered an objection or had significant concerns about vaccination, this suggests "that there has been little change in the overall impact of vaccination objection since 2001", contrary to claims in the media that parental refusal was increasing.
Beard and his colleagues advised clinicians to be "on the alert for appropriate catch-up opportunities for partially vaccinated children, as in most cases they are probably not up to date for reasons other than parental objection."