This tweet from today caught my eye:

One picture that will convince everyone to vaccinate their kids http://t.co/cPH5cnbd9C — ThinkProgress (@thinkprogress) April 8, 2014

The smart folks at ThinkProgress seem to have missed all themediacoverage of this recent study, which found that, for those already suspicious or concerned about vaccines, images of sick children and dramatic, cautionary narratives "actually increased beliefs in serious vaccine side effects." This is a known as the "backfire effect," a phenomena defined concisely here:

When your deepest convictions are challenged by contradictory evidence, your beliefs get stronger.

Two of the researchers (Brendan Nyhan and Jason Reifler) who have previously written about the "backfire effect" in the context of political issues, are the lead authors of the recent study on ineffective vaccine communication approaches. (I discussed their paper here several weeks ago.) The study's results suggest that vaccine-hesitant parents are immune to pro-vaccine messages and scary warnings, leading the authors to ask:

how should physicians and public health agencies respond to parental questions about vaccine safety? This question is difficult to answer. For instance, while some have advocated that health professionals engage in dialogue with vaccine-hesitant parents, relatively little is known about which messages are effective in overcoming parental reluctance to vaccinate.

But some are working assiduously to discern which messages are effective. On this front, I was encouraged to learn recently about Julie Leask, a professor of public health at the University of Sydney, in Australia. (Hat tip to Dan Kahan, who also has relevant vaccine-related papers here and here.) Leask has written about her work here and here and laid out seemingly effective communication approaches in this 2012 paper. Several weeks ago, I had an email exchange with Leask, in which she elaborated on her research findings. Below is a lengthy excerpt from her that spells out some of the strategies now being used to communicate with vaccine-hesitant parents: The immunisation social research field has come a long way since parents were dichotomised into the unhelpful labels of pro- or anti- vaccine. First, there is a spectrum of positions parents can have on vaccination - unquestioning acceptance, cautious acceptance, hesitance, delaying or selectively vaccinating and not vaccinating at all. Second, parents may move between these positions over timeThe key is in health care providers first finding out where parents are at. Our research estimates that about half of all parents have no concerns and will just have their child immunised without thinking much about it - or they will even be vocal advocates. Another 40% have just a few questions or concerns. About 12% have a lot of questions or concerns and will either fully or partially vaccinate their child and only about 2% don't' vaccinate at all because they have so many concerns about vaccination.Those hesitant parents - if their concerns are not addressed well can end up not vaccinating at all. That discussion with their doctor or nurse is pivotal. So in using a tailored approach, four things are helpful:1. Find out where parents are at on this spectrum.2. Establish flexible goals according to where they are at. A lot of time is wasted arguing with a mum who has no intention of vaccinating when it would be much better to keep the discussion brief but aim to leave the door open for future discussion. On the other hand, if mums or dads are genuinely concerned but have some motivation to vaccinate, health professionals might like to invest a bit of extra time with them. Maybe make another appointment.3. Use the most appropriate strategy to meet those goals. For hesitant parents, motivational interviewing techniques might help. They use a guiding style, instead of a directing style. This can still start with a confident recommendation about vaccination. But it then finds out where parents are at. There is a lot of focus on resisting the temptation to right wrong information. It is much better to first understand what those concerns are and what might be their source. For example, there might be a family member who had a reaction to a vaccine. Having established their level of confidence and concern about the vaccine the second part of motivational interviewing is exploring a parent's own motivation to vaccinate. By getting them to voice that, they verbally engage the positives of vaccination and the health professional has the opportunity to elaborate on any point the parent might have made. This is true engagement instead of the top down paternalism that inevitably fails with such parents who tend to value their autonomy a great deal.4. Use quality information, targeted to the parent's needs. There are many vaccines on the schedule for children and hence much to communicate. If possible, it is better to get the information ahead of time. If not, providing some basic information about the vaccine and also what side effects to expect is very important to parents.As parents or patients, we all want our questions to be taken seriously and answered well. It is normal to want to know about the few risks of vaccination, along with what sort of diseases they are protecting babies and children against. Recognising that parents come from a genuine wish to protect their children but also be confident in the vaccines they are having is important. For example, about one quarter of parents are concerned about the effect of vaccines on the immune system of their young baby. This is an intuitive concern that can be readily addressed. But health professionals we often need to resist the temptation to hear a concern we think is wrong and jump in to 'right the wrong'. That is why communication science advises professionals to resist the righting reflex but use a guiding style.