Why the rise in vaccine objectors?

Vaccine objector rates are rising in Australia. In 1999 they were 0.23% and by September 2014 they were 1.79%. This is nearly an eightfold increase in relative terms and a 1.56% increase in absolute terms. Vaccine objector rates are based on those who formally register their objection using this form. The form must be signed by an immunisation provider or doctor and the parent and submitted to the Department of Human Services. It is required by parents who are not fully vaccinating their child (i.e., not vaccinating at all or partially vaccinating or delaying vaccination) to continue to receive certain government payments, childcare rebate (if they are eligible) and entry to childcare in some states.

Vaccine objector rates have risen - slightly (note the y-axis only goes to 5%)
Vaccine objector rates have risen – slightly (note the y-axis only goes to 5%)

There has been a lot of concern expressed in the mass media about this rise in vaccine objectors. The spotlight burnt brightly once vaccination rates first became really public in April 2013 when the National Health Performance Authority released regional level data. People were naturally worried about what this might represent. Societies can usually withstand a small handful of vaccine objectors but it doesn’t take much of an increase to tip us over into outbreaks. The most stark example was when the UK’s MMR scare led parents who would usually fully vaccinate, to delay or decline MMR vaccine, leaving them with a measles epidemic.

Is this rise in objector rates because diseases like polio and diphtheria are going from memory, ironically with the success of vaccines? Has the internet’s capacity to rapidly deliver misinformation to parents created a rising tide of fear and misapprehension? Or are we seeing a shift in parenting styles – the ‘professionalized mother’ who spends time and resources deciding what her child needs but in that process sees vaccines as just a technology for individual consumption, as this study found?

The problem is that we don’t really know why vaccine objector rates have risen. There has been no corresponding decline in coverage rates. Then there is this mysterious group of children who are not registered as objectors but have no vaccines recorded on the Australian Childhood Immunisation Register. They were estimated to be 3% of children in 2013.

Nationally, the proportion of children with no vaccines recorded has reduced to 2.31% at the same time there was a slight uptick in registered objectors. This suggests that at least some of the parents who were ‘silent’ (non registering) objectors have shown their hand. A recent study of this group in WA helps shed light on who they are. It found that 28% were unregistered vaccine objectors. Also, in 44% the family had moved from overseas and the child’s previous immunisation history had not been added to the Australian Childhood Immunisation Register. An important caveat with this study, is that the researchers were only able to speak to 29% of the 834 they aimed for. However, the overall picture is that ‘no vaccines recorded’ is a mix of children who are truly not vaccinated at all and about half who are partially vaccinated but they don’t make it to the register.

The recent reduction in ‘no vaccines recorded’ and a corresponding increase in registered vaccine objection makes sense. In July 2012, the federal government linked Family Tax Benefit part A to completed vaccination of children (described in more detail here). This payment is up to $2100 per child paid to the approximately 73% of families who were eligible. It used to be linked to the Maternity Immunisation Allowance which was much smaller. So by linking this larger payment more parents would be motivated to register an existing objection – they now had more to lose by continuing to not vaccinate. We have also seen a tightening up on childcare entry requirements in NSW meaning that full vaccination or registered objection is being more strictly enforced before children can enrol.

At what point will vaccination objector rates hit a ceiling? They were was 1.79% in September 2014. Will they rise to 2.5% or 3%? Because our immunisation rates remain stable, the objection rate is unlikely to rise much above 3% unless Australia gets a vaccine safety scare.

It is not certain whether the rise in official vaccine objectors is only about people who were always objectors now registering. The best way to tell would be to track attitudes over time and include a more direct question. But this is not happening at present. I am working with researchers who have the expertise to develop and deploy a good quality survey but this needs funding like any other quality research endeavour. It is an important investment. The UK reaped the benefits of such a survey at the height of the MMR vaccine scare when they were able to track mother’s attitudes to MMR vaccine and predict accurately ahead of time when coverage would decline. Meanwhile, we will have to keep guessing what is happening to vaccine sentiment in Australia.

As we point out in this recent article, vaccine hesitancy is a growing concern. Countries all over the world see groups of parents who partially vaccinate or do not vaccinate their children at all out of choice. Much more needs to be done to see if hesitancy is growing, what drives it, and what governments can do about it. Vaccine refusal is the tip of the ice-berg. Many parents fully vaccinate but are still quite hesitant. What might tip them over?

A vaccine would never be unleashed on a population without data on the disease itself using good diagnostic tests and surveillance. Then the vaccine must be tested to ensure it is effective and safe. The same goes for vaccine hesitancy. It is not enough to assume hesitancy is rising. It needs to be measured with decent indicators and over time in populations of parents. Governments also need solutions that are well tested so they are effective and don’t cause unintended harms. This can only happen with a strong evidence base. We demand it for vaccines. We should also demand it for the solutions to vaccine hesitancy.

COI: I am involved in a number of research funding applications to develop ways to assess and address vaccine hesitancy.

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