Vaccines and Evidence-Based Medicine: A Q&A with Sean Young, PhD

Researchers have discredited studies that link autism to vaccines, yet it remains a topic of concern for some parents, particularly among the affluent. What’s your take on why this remains an enduring issue in the news?

It’s easy to find associations between things. Sometimes those associations are true, sometimes they aren’t. For example, a classic example is the association between eating ice cream and death by drowning. Someone could look at that link and say that eating ice cream causes drowning, but that would obviously be false. The real reason for the link is that people eat ice cream on hot days, and they also go swimming on hot days. When it’s hot, you find more people eating ice cream and drowning, but it’s not that ice cream causes drowning, it’s that both happen together on hot days. A common expression you’ll hear in cases like this is “correlation does not imply causation.” That is, having two things happen together doesn’t mean one thing necessarily caused the other.

How does this relate to autism? People have seen an increase in autism and they are scared, and they’ve also seen an increase in vaccinations during roughly the same time period in the late 20th century. Some people see these associations and start making claims that vaccines cause autism, but science doesn’t back up those claims. But it’s a compelling argument because it’s built a base among educated, affluent people who are scared their kids will get autism. When people are fearful, it’s hard to use science or facts to convince them that their fears are unfounded – people’s fear, rather than science, takes precedence. Problems that elicit fear and other strong emotions make good news because people will pay attention.

Have you used social media to help people understand the benefits of adhering to a vaccination schedule or general medication schedule?

We haven’t done anything around using social media to change people’s perceptions of the link between vaccines and autism or other health problems. I have, however, talked in a previous post about how data can be used to understand and predict events. Because people readily share their views about vaccines, we could apply similar methods to mine social media data about vaccines and use that to predict whether people support vaccines and how this support would affect vaccination rates and disease outbreaks.

Despite advances in understanding both HIV and the human immune system, a fully successful vaccine to treat HIV is still not available. Do you have hope that one might still be developed, or do you feel other preventative therapies such as PrEP are as far as we’ll go?

I have hope, but I don’t think anyone knows the answer to this question. One current approach is to use genetics/genomics approaches to change genes and target HIV susceptible and infected cells.

Do you agree with doctors who have implemented a policy of only treating children who have been immunized according to the American Academy of Pediatrics schedule? And more generally, what do you see as the core behaviors/belief systems that might cause people to not have their infant vaccinated?

As a scientist, I trust that science is the current best approach, whether it’s science recommended by the American Academy of Pediatrics or other organizations. All that matters to me is whether it’s good science, as opposed to poor science like the correlation relationship I described above. Science might not always prove to be right, as new results emerge and testing methods change, but at any given time I trust that scientific approaches are best. Rather than focus on what causes people to not have their infants vaccinated, I prefer to focus on what is working and leverage that science. We know that social norms have a tremendous affect on what people do, and that extends to vaccines. By creating a social norm that encourages people to vaccinate their kids, such as by using the HOPE social media model, I think we can make major changes in vaccination rates and reduce the spread of diseases caused by lack of vaccination.