How to promote the safety and effectiveness of vaccines

In a few months, my son will get the MMR vaccine. I count myself very fortunate to live in a place and time when this amazing protection against is made available for free, and I will of course have him vaccinated. When I had my oldest child vaccinated, nearly 10 years ago, there was (at least where I lived, Belgium) no vaccine debate. I was dimly aware there were some very religious people who refused vaccines, but they were so clearly an outgroup that people did not seriously consider them and their arguments. Not vaccinating didn't even seem like a live option to me. Now, fast-forward post-Wakefield UK…

Vaccines are no longer the obvious, uncontroversial medical procedure they once were. "Are you planning to have your baby vaccinated" (ask healthcare visitors) And if I say yes,  I hear what a wise decision it is, and that I need not worry about autism. In fact, NHS leaflets, baby books and other materials invariably tell me (rightly) that the link between vaccines and autism has been debunked. Yet I caught myself thinking "Is it really safe?" This thought was followed by "Of course it is, why am I even thinking this!" Thanks to my scientific training and background in philosophy of science, and my access to journals behind paywalls, I am able to read and interpret the retraction of the original research. But many parents are not in my position and have to rely on various lines of testimony. By trying to assuage fear brought about by anti-vaxxer campaigns, these materials are in effect playing into them, by acknowledging there's still a controversy (the UK numbers are recovering from the decline brought about by Wakefield's research, so hopefully this trend continues). 

It is a well-known phenomenon that it's impossible not to think of a polar bear who's driving a red car, when I've just put that thought into your mind as you are reading it. Similarly, all the leaflets that try to debunk the autism-vaccine link vividly put in parents' minds that vaccines might somehow cause autism. Recent research shows this is no fringe concern: a recent survey found that only 37% of parents disagree with the statement that vaccines cause autism. Even 39% of parents who are pro-vaccine say they are unsure. The reason is precisely because vaccines and autism have been linked in the public eye, and anti-anti-vaccine campaigns that want to debunk this are in effect strengthening the association.

But fears about autism, no matter how irrational and ungrounded, cannot entirely explain why some parents are so dead set against vaccines. One recent study by Brendan Nyhan et al. in Pediatrics found that debunking the vaccine-autism link does help to decrease the perceived risk, but this does not change anti-vaccine parents. In fact, surprisingly, finding out they were mistaken in believing this link made the parents even more, not less, likely to reject vaccines. This is a deeply troubling finding. Even more troubling, none of the campaigns they tested seemed to sway anti-vaccine parents' opinions. The Slate commentary states that this is simply due to the fact that "people become more assured of their stupid opinions when confronted with factual or scientific evidence proving them wrong." Even if that is true, there used to be a lot of sentiments against vaccines before (when they were first introduced), as there were against other medical inventions. So we need to focus again, I think, on pro-vaccine campaigns instead of anti-anti-vaccine campaigns. The primary message shouldn't be "Here's why anti-vaccine campaigners are wrong", but "Here's why you should have your children vaccinated". 

One of the great modern campaigners for vaccines was Lady Mary Wortley Montagu, who introduced inoculation against smallpox in England nearly 80 years before Jenner. Her introduction of a Turkish technique of inoculation made Jenner's later experiments and his development of vaccination (a safer procedure, as it used cowpox) possible. She learned about inoculation by seeing it performed by Greek women in Turkey, where she was living with her husband (who was an ambassador). Upon her return to England, she enthusiastically promoted the procedure, but there was a lot of initial distrust of the method, as it came from the east and thus was thought prima facie unreliable. Lady Mary Wortley offered both her son and daughter as subjects to prove the reliability of the method. To further convince skeptics, she anonymously published "A Plain Account of the Inoculating of the Small Pox by a Turkey Merchant" in a London newspaper (I have been unable to find a copy online, unfortunately).

Lady Montagu was able to successfully promote inoculation as a proven technique to prevent smallpox, a remarkable feat given the initial distrust of the procedure, and the 3% mortality rate of her technique, which was vastly better than catching the disease (up to 40% mortality rate, but still a great deal less safe than today). We can learn from her story and others on how to develop on a positive message of pro-vaccine, rather than anti-anti-vaccine. Debunking is fine, and but it needs to be accompanied with a cultural sensitivity (as Kahan puts it) for the doubting parents, treating them not as idiots but as people whose concerns and fears are taken seriously.

Kahan argues (and has empirical support) for his claim that the medium in which the message is brought is of vital importance to convince a doubting public of the reality of things like climate change. Debunking by itself, or websites with death counts, are unlikely to sway skeptics and may even lead to an undesirable polarization of attitudes. From a consequentialist perspective, our primary focus should not be to prove the anti-vaccine promoters wrong but to make sure to create a climate where parents again accept vaccination as the obvious, safe choice for their children. As Lady Montagu wrote " 'Tis no way my interest (according to the common acceptation of that word) to convince the world of their errors; that is, I shall get nothing by it but the private satisfaction of having done good to mankind, and I know no body that reckons that satisfaction any part of their interest."