Vaccine hesitancy, a persistent issue since the 19th century, has gained renewed momentum in the United States, with Robert F. Kennedy Jr., a prominent figure in the anti-vaccine movement, now leading the US Department of Health and Human Services. This development comes at a time when national vaccination rates for children are declining, raising concerns about the resurgence of preventable diseases. According to recent surveys from the Annenberg Public Policy Center of the University of Pennsylvania, the proportion of individuals who believe vaccines are unsafe has increased from 9% in April 2021 to 16% in the fall of 2023.
The decline in vaccination coverage is particularly alarming among kindergarteners, where rates have dipped since 2020 after a steady prior decade. More than 30 states reported decreased vaccination rates for diseases such as measles, mumps, and rubella (MMR); diphtheria, tetanus, and pertussis (DTaP); polio; and varicella in 2024 compared to 2023. These falling numbers suggest that vaccination levels for children have fallen below the herd-immunity threshold for numerous preventable diseases, including mumps, whooping cough, and measles. The gravity of this situation was underscored by a recent tragic case in west Texas, where an unvaccinated child succumbed to measles after hospitalization.
The roots of vaccine hesitancy can be traced back to the mid-19th century when the anti-vax movement first emerged in response to mandatory smallpox-vaccination laws. Today, cognitive dissonance—a psychological phenomenon where conflicting beliefs lead individuals to entrench further in their views—plays a significant role in sustaining vaccine skepticism. Dr. Joe Pierre, a professor of psychiatry at the University of California at San Francisco, explains that conspiracy beliefs are often fueled by psychological needs such as uniqueness, a sense of control, and social affiliation.
"Cognitive dissonance, the tension that arises when our beliefs butt up against reality, is typically resolved by digging our heels in even deeper," says Dr. Joe Pierre.
The challenge lies in how institutions can effectively present the truth in ways that resonate psychologically with vaccine skeptics. As Dr. Pierre notes, understanding the underlying concerns and needs of vaccine deniers is crucial to convincing them otherwise.
"To convince vaccine deniers, it's essential to present the truth in a way that is psychologically appealing and to address their underlying concerns and needs," according to Dr. Joe Pierre.
Firsthand experiences with vaccine-preventable diseases can often serve as a powerful catalyst for changing minds. Kristen O'Meara's story highlights this phenomenon. After witnessing all three of her children suffer through severe cases of rotavirus, she experienced a wake-up call that shifted her stance on vaccination.
Dr. Devon Greyson, a health information scientist, has conducted extensive research on mothers who have altered their views on vaccines. Her study in 2022 involved interviewing 23 mothers in Vancouver, Canada, about how their vaccine attitudes evolved over time. Greyson's work aims to "reverse engineer" the process of changing vaccine perceptions.
“to ask questions of trusted experts, identify reliable sources and remain intellectually flexible,” encourages Greyson.
Some individuals, like Johnson, have described feeling manipulated by authoritative figures within the anti-vaccine movement.
"It's very manipulative. You see somebody speaking with authority, and you just feel like, that's the truth," remarks Johnson.
These experiences are compounded by anecdotes shared within communities about perceived vaccine injuries.
“I remember someone in the community talking about their child who had been ‘vaccine injured’,” recalls Johnson.
Greene shares a similar narrative, recounting how fear and misinformation contributed to her skepticism.
“I found people saying: ‘They’re never going to admit it’s a vaccine side effect, but [your baby’s] brain is probably inflamed, she’s probably in pain,’” shares Greene.
The decision-making process around vaccines is often influenced by personal experiences and perceptions of risk versus benefit. Dr. Pierre points out that many individuals weigh these factors based solely on their own experiences.
“Part of the problem is that people often weigh risks and benefits of vaccines based solely on themselves,” notes Pierre.
“They think: ‘I had a flu shot last year and I got the flu anyway,’ or: ‘I haven’t had the flu in five years and I never get vaccinated,’” adds Pierre.
Washington state's former secretary of health, Dr. Umair Shah, has suggested that it may take the death of an influential figure from a vaccine-preventable disease to reignite wider acceptance of immunizations. This sobering possibility underscores the urgent need for effective communication strategies that address vaccine hesitancy head-on.