The refusal of many people in the United States to get vaccinated has helped lead to a new surge of COVID-19 cases. But as a paper that health researchers Diane S. Saint-Victor and Saad B. Omer wrote back in 2013 shows, this kind of dynamic is not unique to our nation or our political moment. Vaccine refusal has stymied the eradication of many diseases.
On its face, Saint-Victor and Omer write, vaccine administration is much simpler than many other public health interventions.
“Unlike other methods of infectious disease prevention, vaccines do not typically require drastic and costly changes in human behavior, sanitation practices or sexual networks,” they write.
But that doesn’t make them a foolproof solution. In many cases, the introduction of a vaccine into a population initially pushes case rates and deaths down, but this is followed by a plateau. With the disease no longer such a pressing concern, people become less worried about getting vaccinated. Meanwhile, any adverse effects from the vaccine attract public attention, increasing worries about getting the shot.
“The disappearance of a disease from the public eye creates a paradox whereby the success of a public health campaign (widespread vaccination and disease prevention) becomes a serious obstacle to the campaign itself,” the authors write.
For some people, vaccination campaigns addressing diseases that aren’t currently a major local problem can feel like a distraction from other issues. The authors quote a butcher in Nigeria who criticized a 2005 vaccination campaign against polio, noting that many people were sick with other diseases and had no money for medicine.
“Help them instead,” he said. “But no! You find a small baby who is well and drop medicine in his mouth for free!”
These dynamics mean that, somewhat ironically, it’s often hard to eradicate a disease that’s been controlled. For example, between 1989 and 2000, the number of measles cases dropped by more than 50 percent, but then plateaued (and, since the time of the article’s publication in 2013, they’ve jumped again).
One exception to the pattern was the international effort to eradicate smallpox that began in the late 1950s and succeeded within two decades. Why was this campaign so successful? Saint-Victor and Omer write that certain aspects of the disease itself helped. The pox are visible and leave scars, making it hard for communities to remain unaware of its presence. In the mid-twentieth century, vaccine resistance also happened to be low in some of the most vulnerable places. In West Africa, the success of penicillin injections in reducing yaws—an infectious, debilitating disease—in the 1940s may have led communities to favor the idea of injected medicines. Meanwhile, officials in India and some other Asian countries made it a political priority to avoid being the last country suffering from smallpox.
Absent those kinds of dynamics, continuing difficulties in getting the United States, and the world, vaccinated against COVID-19 may be intensely frustrating but not terribly surprising.