Truth decayExplaining public resistance to vaccination

Published 26 March 2019

Low vaccine compliance is a public health issue that can cause the loss of “herd immunity” and lead to the spread of infectious diseases. Low vaccine compliance is a public health issue that can cause the loss of “herd immunity” and lead to the spread of infectious diseases. In parts of Europe and North America, childhood diseases like measles, mumps and pertussis have returned as a result of insufficient vaccination coverage. Why is it so challenging to increase the number of people who get vaccinated? How does popular resistance to vaccination remain strong even as preventable diseases make a comeback?

nti-vaccination movement sometimes moves to conspiracy theory // Source: commons.wikipedia.org

In 1998, the respectable British Medical Journal (BMJ) published an article by Andrew Wakefield, which connected autism with the measles, mumps, and rubella (MMR) vaccine. The article raised skeptical eyebrows shortly after its publication, but it took the journal twelve years to retract the paper (see “Wakefield’s article linking MMR vaccine and autism was fraudulent,” BMJ, 6 January 2011). By then, however, the contents of the fraudulent article had been broadly disseminated.

In 2006, investigative journalist Brian Deer revealed in the Sunday Times of London that Wakefield had been paid over £400,000 to fabricate his findings.

But it was too late. A small but loud and aggressive group, consisting of fringe conspiracy peddlers and worried but misinformed parents, took Wakefield’s bait.

A new study set out to find answers to these questions: Why is it so challenging to increase the number of people who get vaccinated? How does popular resistance to vaccination remain strong even as preventable diseases make a comeback?

A study, from Dartmouth College, shows that past problems with vaccines can cause a phenomenon known as hysteresis, creating a negative history that stiffens public resolve against vaccination. The finding explains why it is so hard to increase uptake even when overwhelming evidence indicates that vaccines are safe and beneficial.

Dartmouth notes that a hysteresis loop causes the impact of a force to be observed even after the force itself has been eliminated. It’s why unemployment rates can sometimes remain high in a recovering economy. It’s why physical objects resist returning to their original state after being acted on by an outside force. And, according to the Dartmouth research, it’s why the public resists vaccination campaigns for ailments like the common flu.

Given all the benefits of vaccination, it’s been a struggle to understand why vaccination rates can remain stubbornly low,” said Feng Fu, an assistant professor of mathematics at Dartmouth College. “History matters, and we now know that hysteresis is part of the answer.”

The research, published in the journal Proceedings of the Royal Society B, is the first study to demonstrate that hysteresis can impact public health.