The WHO names a major threat to anti-Vax health: hysteresis might describe a move

January 18, 2019

The WHO ranked vaccine hesitation among the top 10 threats to global health in 2019.

The World Health Organization (WHO) ranked vaccine hesitancy among the top 10 threats to global health in 2019. "Hesitating to vaccination – reluctance or refusal to vaccinate despite the availability of vaccines – threatens to reverse the progress made in the fight against vaccine-preventable diseases, "wrote the United Nations Public Health Branch.¹

Although the vast majority of parents vaccinate their children according to the vaccination schedule recommended by the Centers for Disease Control and Prevention, the percentage of children who have not received any of the 14 recommended vaccines has more than quadrupled, from 0.3% to 1.3% since 2001.²

The WHO points to a "3C" model to explain why people refuse to vaccinate. The 3 Cs are synonymous with convenience, convenience and trust. Complacency occurs when the perceived risk of illness is low and vaccination is deemed unnecessary. Convenience is measured by the extent to which availability, affordability, willingness to pay, health knowledge and other potential barriers prevent vaccination. Confidence refers to mistrust of the safety and efficacy of vaccines, the system that provides them, and the motivations of decision makers who decide which vaccines are needed.³

In a study published in Acts of the Royal Society BResearchers at Dartmouth College have explained that hysteresis may describe persistent skepticism with regard to vaccines.⁴ The hysteresis describes how a system depends on its history and how the impacts of a force can persist long after the initial force has been altered or eliminated. This phenomenon can be observed in many physical systems but also in society. In the context of vaccines, this prevents an increase in vaccination rates, even after the removal of negative objections. As a result, society is more vulnerable to epidemics.

"Once people have questioned the safety or efficacy of a vaccine, it can be very difficult to get them to overcome these negative badociations," said Feng Fu, an badistant professor. of mathematics at Dartmouth College, who led the research. "Hysteresis is a powerful force that's hard to break down socially."⁵

"This study shows why it's so difficult to reverse low or declining vaccine levels," added Xingru Chen, a graduate student at Dartmouth College, who co-authored the article. "The strength of factual and logical arguments around public health issues is simply not enough to overcome hysteresis and human behavior."⁵

The researchers hope that by identifying the effect of hysteresis during vaccination, public health officials can create campaigns to increase voluntary vaccination rates, including promoting them as altruistic behavior. and socially desirable.

References

1. Ten threats to global health in 2019. World Health Organization. Accessed January 18, 2019.
2. Hill HA, LD Elam-Evans, Yankey D, et al. Immunization coverage for children aged 19 to 35 months – United States, 2017. Morb Mortal Rep Wkly. 2018; 67 (40): 1123-1128.
3. Report of the SAGE Working Group on Hygiene Incidence. World Health Organization. November 12, 2014. Accessed January 18, 2019.
4. Chen X, Fu F. Imperfect vaccine and hysteresis. Proc Biol Sci. 2019; 286 (1894): 20182406.
5. Research explains public resistance to vaccination [press release]. Hanover, NH; Dartmouth College; January 9, 2019.