So Malcolm Turnbull's recent call for states and territories to ban unvaccinated children from daycare and preschool – hot on the heels of Senator Pauline Hanson's widely repudiated and harebrained remarks on vaccination – should come as no surprise.

Let's face it, public condemnation of "vaccine refusers" is not just at an all time high, it's almost universal.

The only people still prepared to turn a sympathetic ear to "vaccine hesitant" parents are, curiously, paediatricians and public health experts – who are not the ones spearheading the campaign, dubbed "No Jab, No Play".

While many immunisation experts caution against punitive approaches and retain significant reservations about the Commonwealth's "No Jab, No Pay" policy, it's not clear anyone's listening. The PM's grand plan is looking more and more like policy on the run, but who cares? 

But – much as I won't be popular for saying so – if there's nothing to be lost in laying into the "anti-vaxxers", what's to be gained? Aren't there better alternatives to punitive measures? 

There aren't easy answers to any of these questions, but before we embark on reforms that could see stringent restrictions, nationally, on childcare enrolments which may compound disadvantage for some vulnerable children, shouldn't we at least be asking?

Research led by Associate Professor Julie Leask from the School of Public Health at the University of Sydney reveals that only around a third of parents unquestioningly accept vaccination, and a significant portion of the remainder have "many concerns" but comply with the vaccination schedule anyway.

Less than 2 per cent will refuse all vaccines, for a range of reasons.

It's hardly going out on the limb to suggest that we need to understand the reasons parents refuse vaccination if we want to tailor public policy effectively. 

But this research – backed up by Australian statistics on registered conscientious objectors – also reveals that entrenched "refusers" are actually a very small subset, and policies might be better targeted at the larger group of parents who are either undecided or who confront logistical barriers.

Indeed, given the small number of conscientious objectors across the country, it's possible that optimal vaccination rates of around 95 per cent could be achieved even without shifting this group.

Of the 7 per cent of Australian children who are not fully vaccinated, more than half have been prevented by practical barriers, rather than philosophical objections.

And when it comes to the committed vaccine refusers, they may present a diabolical policy problem but it's far from clear they'd respond to Turnbull's proposed policy approach.

If experience in NSW and Victoria is any indication – the former allowing conscientious objection and the latter only allowing exemption on medical grounds – a hard-line approach may make little difference to vaccine refusal rates.

The NSW experience suggests a more nuanced approach to "No Jab, No Play" – requiring a vaccine objection form to be co-signed by a GP – is likely to be equally effective as its hard line alternative.