Feb 03 2017

Pew Vaccine Survey – Some Good and Bad News

Pew recently published a surveyvaccines-Pew-2017 looking at the attitudes of Americans regarding the safety and effectiveness of vaccines. The results are not surprising, but there are some interesting bits in the data.

The headline main results are that 88% of those surveyed thought that the benefits of vaccines outweigh the risks, while only 10% thought the risks outweigh the benefits. Further, 82% supported mandatory vaccinations for healthy school children.

This is both good and bad news. It means a solid majority of Americans understand that vaccines are safe and effective. However, the minority who doubt the safety of vaccines are enough to cause problems. Also, those numbers are a bit worse when you dig into the data.

Parents of young children, age 0-4, were more negative about vaccines, with only 81% stating that the benefits outweigh the risks, compared to 91% of those with older children and 90% of those with no children.  Parents of young children are the ones deciding if they get vaccinated. The reason for this is likely that parents with young children are facing the decision of whether or not to vaccinate and are looking for information online. They are therefore more likely to come across anti-vaccine propaganda. Parents of young children may also be easier to scare than more experienced parents.

These numbers are important because of herd immunity – if enough of the population is vaccinated, then a disease outbreak cannot find enough susceptible hosts to spread and will therefore peter out quickly. This will keep the disease from being endemic, meaning that it is self-sustaining in the population.

If vaccination rates drop below around 90% then herd immunity is lost, and diseases that were once gone can once again become endemic and outbreaks will be more common and more severe. This has been happening to measles, for example.

Further, vaccine refusal is not randomly distributed in the population, but occurs in clusters, making outbreaks in those populations even more likely. Even if the overall vaccine refusal rate is low, there can still be pockets where herd immunity is lost.

The Pew data contains some clues as to why this happens. African Americans and Hispanics were more likely to have negative views toward vaccines than whites. The reason for this is unclear, but it may have something to do with the overall trust of the system.

Unsurprisingly, those who use “alternative medicine” were more likely to have negative views toward vaccines. For the heaviest alternative medicine users 26% felt that parents should be able to refuse vaccines for their children even if it puts other children at risk, compared to 13% of those who never used alternative medicine.

This factor likely has several causes, but chief among them is likely the fact that many alternative medicine practitioners and proponents are anti-vaccine. Vaccines, and science-based medicine, are competitors to purveyors of snake-oil, so it helps if you convince your customers that the competitor doesn’t work or isn’t safe. Just look at the ads on any anti-vaccine website and you will see the connection.

Political ideology had little effect on vaccine views, which fits prior surveys showing that anti-vaccine views are bipartisan. However, conservatives were more likely to endorse the parents’ right to refuse vaccines, likely because of libertarian beliefs.

There is what I think is some potential good news in the survey. They also found that those with more science knowledge were more likely to support vaccines, and those who understood what “herd immunity” is were also more likely to support vaccines. This suggests that education should be an effective tool in increasing vaccine compliance.

It does seem from the data that those more likely to be getting their information from the internet are more likely to come across anti-vaccine propaganda as well. This means that we really need to engage in social media and wherever we can on the web to fight anti-vaccine misinformation, and to educate the public about the science and safety of vaccines.

It can be tiring to challenge the same misinformation over and over again, but that is what we need to do. It does seem that people who hold fringe views, or those tinged with conspiracy thinking, are more passionate and tireless. Mainstream scientists and academics, on the other hand, tend to tire easily of the nonsense. So there is a fundamental asymmetry in which the fringe voices (which are often wrong) tend to be louder and more persistent.

I do, however, think there is another fundamental asymmetry in that the science-based position is better supported (by definition) by facts and logic, and that does carry a certain advantage. This is not a definitive advantage, but it does help. It only helps, however, if we get the word out there, which again gets back to being vigilant and just as tireless as the promoters of dangerous nonsense.

The survey also suggests that, yet again, society benefits when the population is more scientifically literate. We need to improve education in science and critical thinking in general, and continuously correct the record on vaccines specifically.

Meanwhile, there is already a solid majority of Americans who support vaccines, and they need to make their political voice heard (especially now that we have a president who is demonstrably anti-vaccine).

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