Commentary: Vaccines—Protecting Health and Saving Lives

There is no doubt that vaccines are one of the most important medical breakthroughs of the 20th century. Why? Consider the polio epidemic as an example. In 1952, at its peak, nearly 60,000 Americans had polio. That year, 3,000 people died of it, and more than 20,000 were paralyzed. But by the early 1960s, polio had largely been eradicated in the United States, thanks to the polio vaccine and a far-reaching immunization program. Measles used to be one of the world’s leading killers of children, accounting for millions of deaths each year. Now, because of the measles vaccine, less than 100,000 worldwide die annually. In fact, global campaigns for vaccination against polio, diphtheria, pertussis, tetanus, and tuberculosis have saved millions of lives. This is a huge accomplishment in public health.

Indeed, the magnitude of the impact of vaccines is enormous. According to the U.S. Centers for Disease Control and Prevention (CDC), vaccines given to infants and young children over the past 2 decades will prevent 322 million illnesses, 21 million hospitalizations, and 732,000 deaths over the course of their lifetimes. Vaccines also will have saved $295 billion in direct costs, such as medical expenses, and a total of more than $1.3 trillion in societal costs over that time, because children who were spared from sometimes-devastating illnesses will be able to contribute to society (Whitney, Zhou, Singleton, & Schuchat, 2014).

In this context, it is unsurprising that vaccines enjoy broad support from all sectors of society. However, vaccination is no routine matter for a small segment of society. Vaccination has had its critics since the introduction of Edward Jenner’s smallpox vaccine. Many different types of objections have been raised in response to vaccines. Some have questioned the science of vaccination. Others have focused on the personal-liberty interests at stake and have objected to the paternalistic nature of government imposition of what is viewed as a personal medical choice. Furthermore, others have opposed vaccination for personal or religious reasons. In addition, the decline of many diseases for which vaccination is still mandated may make some parents skeptical of the continued wisdom of subjecting a child to a vaccine, even if the vaccine is considered extremely safe.

In recent years, the false belief that vaccines are linked to autism has driven many antivaccination efforts. Fueled by junk science, some parents choose not to vaccinate their children, mistakenly believing that vaccines cause autism or might otherwise somehow harm their children, even though the National Academy of Medicine and many other medical organizations have repeatedly debunked these beliefs on the basis of undisputed scientific evidence (Institute of Medicine, 2012). For more information, see the Institute of Medicine’s Immunization Safety Review Series (https://www.nap.edu/initiative/immunization-safety-review-committee).

A major problem with opting out is that vaccines are effective at protecting a community only when there is “herd immunity”—in other words, when a critical mass is immunized. For the measles vaccine to work, for example, 92% to 95% of a population needs to be vaccinated to ensure the whole area is protected. In a small community, that means a few households that opt out of the vaccine could be putting their neighbors at risk.

That is exactly what happened in Minnesota this year, and the results were devastating. Minnesota had 79 cases of measles in 2017. In comparison, 86 people from 16 states were reported to have measles in 2016 (CDC, 2017). The outbreak primarily affected children within a Somali community who were not vaccinated (Hall et al., 2017). Before this outbreak, antivaccine groups that tout the false link between vaccines and autism preyed on parents’ fears by repeatedly handing out literature and speaking at community health meetings. As a result, the vaccination rate in this community in Minnesota dropped dramatically: from 92% in 2004 to just 42% in 2014 (Sun, 2017).

Incidents such as this are especially frustrating because we know without a doubt that these conditions are entirely preventable. The evidence is clear that vaccines are safe and effective.

However, condemning individuals that fail to vaccinate themselves or their children will not solve the problem. Instead, we must find ways to communicate with such individuals and understand the basis for their beliefs. As Brewer and colleagues note in this issue, psychological science offers insight into why people engage in health behaviors including vaccination. Indeed, Brewer and colleagues are performing a service to society by integrating the disconnected literature on psychological theories and vaccination, which can inform practical interventions to address the challenges of vaccination.