The government’s ‘no jab, no pay’ policy, which will restrict childcare benefits for those parents who refuse to have their kids immunised, may seem harsh to some. Most parents, however, will see the wisdom of a policy which puts the collective welfare of all children above the conscientious objections of a few parents.

The rate of non-immunisation of children has risen from 1% to 2% in a decade, noted Tony Abbott at a Sunday morning press conference announcing the new policy. 40,000 children are not immunised in Australia, he added, and rates of some very avoidable but potentially lethal children’s diseases such as measles and whooping cough have gone up.

That 2% put at risk the other 98%, and using the tax and benefits system to send that message is tough, but justified.

In the United States and the UK, too, immunisation rates have fallen over recent years, and diseases which once plagued our children, and were then all but wiped out by immunisation programs, have returned in significant numbers. So what has been going on? Why are so many parents refusing to take advantage of a preventive medical technology which has saved literally millions of children’s lives across the world?

One answer, if not the only one – some have deep religious objections, for example – is the news media, and their role in what we might call the amplification of irrational anxiety.

A small but significant minority of parents have come to believe, in all sincerity (and no-one doubts that they have the best interests of their children at heart) that immunisation is dangerous, and certainly riskier than the risks associated with not having their kids vaccinated.

Even though there is no solid evidence to support that belief, and plenty of evidence to support the benefits of immunisation, some parents are so anxious that they will put their own children, and more importantly, other people’s children, at heightened risk of exposure to a preventable disease which could cause disability and even death.

So where have these anxieties come from?

Back in 1998*, an English doctor by the name of Andrew Wakefield published research claiming to demonstrate a link between the MMR triple vaccine (to immunise children against mumps, measles and rubella) and the onset of autism. As followers of the story will know, Wakefield’s work was subsequently discredited, and he himself struck off the medical register in the UK for his unethical research methods.

Before that happened, however, the alleged risks of MMR became a major news story in the UK and all over the world. At that time, a decade ago, the global incidence of autism had risen dramatically. Between 1996 and 2007 in the United States, for example, the reported incidence of autism rose from 0.8 per 1,000 to 5.2 – an increase of some 600%.

Similar increases were recorded in many other countries. In Australia, the first survey of the prevalence of autism did not take place until 2006 so historical data are lacking. In 2014, however, the Australian Bureau of Statistics found a 79% increase in diagnoses between 2009 and 2012. A NSW parliament report of 2013 noted that:

… the growing number of children diagnosed with Autism Spectrum Disorder (ASD) is an issue of concern both in Australia and overseas.

This does not mean that the actual prevalence of autism has risen, though. Rather, the public awareness of autism has risen, through movies such as Rain Man and the explosion of media visibility around the condition seen since the 1990s. Documentaries were made about autistic ‘savants’, and families where parents struggled to cope with autistic children. The Curious Incident of the Dog in the Night Time became a global publishing phenomenon, and an entire sub-genre of ‘autism lit’ emerged.

Many people, children and adults, who might hitherto have been described as ‘different’ or ‘eccentric’, or even just ‘shy’, were labelled with Asperger’s Syndrome, or some other condition on the autistic spectrum.

Through a heightened media visibility, parents, medical professionals, teachers and others involved with children were sensitised to a condition which until recently was little known and poorly understood. In other words, autism has always existed, but only recently has it been recognised and given a name. As a result, its recorded incidence has risen dramatically, not because more children are acquiring autism from one cause or another, but because more of those born with it – and autism is often a genetic condition that runs in families and mainly affects males – are being identified.

This is a positive development, because autism is very real, and heightened public awareness has led to support services being put in place for people with autism where there had been none.

Notwithstanding this context, one cannot blame parents for becoming more anxious about the causes of autism, and many quite plausible, if never substantiated, theories have circulated. Wakefield’s research, when it was published in 2004, spoke directly to that anxiety, and his hypothesis - that autism was ‘caused’ by immunisation - seemed credible to many.

In the UK, where the scare was centred, and Wakefield’s work taken very seriously by most of the media, hundreds of thousands of parents withdrew their children from the MMR program. Then-prime minister Tony Blair was asked by journalists to reveal if his baby son Leo had been vaccinated or not. He refused to answer on privacy grounds, while making clear his own absolute confidence in the safety of the vaccine.

Despite such reassurances, and the widespread scepticism which greeted Wakefield’s research amongst his medical peers from the outset, the impact of the scare was very real. Rates of immunisation fell, while the incidence of measles and other preventable diseases began to rise. Ill-founded anxiety about the dangers of immunisation ended up having very real consequences on public health.

Years after Wakefield’s work had been discredited by his peers, his theories on MMR and autism have continued to influence parents all over the world. And where he has had influence, so the incidence of the diseases targeted by the MMR vaccine have risen.

In February this year, the Sunday Times reported on the anti-immunisation advocacy of US group Generation Rescue, who were reported to “seek inspiration” from Wakefield, who now lives and works in that country. The result of this campaign:

… say experts, has been to plunge America into the first national debate since the 1970s about the safety and necessity of vaccines — and led to the return of measles, a highly contagious childhood disease judged extinct by the US government’s Centers for Disease Control (CDC) 15 years ago.

In the US, vaccination rates had fallen by 3%, amid what the article called “a mounting sense of panic”. As in the UK a decade previously, erroneous health information spread through a variety of media channels had provoked a health crisis with strong political reverberations.

Politicians faced with anxious parents were encouraged to comment and pronounce on the vaccination ‘issue’, even when ignorant of the science. Republican contenders for the 2016 presidential race – Chris Christie and Rand Paul – both declared their approval of parental exemptions from MMR vaccination.

Rigorous research into media coverage of autism and its causes has not been done in Australia, and we cannot assume that all of those ‘conscientious objectors’ to immunisation are directly influenced by the Wakefield hypothesis. But his work, and the way it was reported a decade ago and since, undoubtedly contributed to a climate of fear around the risks of vaccination, irrational in so far as it lacks foundation in scientifically validated evidence.

The government is therefore right to take strong action against parents whose irrational fears knowingly put other children at risk. It is an example of firm government in the face of myth and unreason, and should be supported by all who care about the health of our kids.

CORRECTION: A previous version of this column said Andrew Wakefield published his paper about MMR in 2004. The Lancet actually published that paper in 1998 – the text has been amended to reflect this.