Influences and beliefs on vaccine hesitancy remain complex

ATLANTA – Before clinicians can learn new and effective strategies on addressing vaccine hesitancy in their practices, they need to understand both the “forest” and the “trees.” That is, it helps to understand the big picture in terms of national trends, and it’s equally important to understand the motivations and psychology of parents who refuse or remain hesitant about vaccines.

Paula Frew, PhD, MPH, of Emory University in Atlanta, pointed out that vaccination coverage of children under 3 years old in the United States remains consistently high. An estimated 93% of children have received at least three doses of the polio vaccine, 92% have received at least one dose of the MMR vaccine, 92% have received at least three doses of the hepatitis B vaccine, and 91% have received at least one dose of the varicella vaccine.

In fact, less than 1% of parents selectively or completely refuse all vaccines – but an estimated 13%-22% of parents intentionally delay vaccines, Dr. Frew said at a conference sponsored by the Centers for Disease Control and Prevention..

She described findings from a study she and colleagues conducted to assess the influence of vaccination decisions among parents of children under age 7 years. They categorized the parents as nonhesitant acceptors of vaccines, hesitant acceptors, delayers, or refusers. Surveys of 2,603 parents in 2012 and 2,518 parents in 2014 revealed that parents overwhelmingly cite their health care provider as their most trusted source of information on vaccines, including 99% of acceptors and 71% of refusers. Among hesitant acceptors, 49% of parents in 2012 and 48% of parents in 2014 said their doctor positively influenced their vaccination decision.

Qualitative findings from focus groups

Still, hesitancy is common enough that qualitative research is seeking to understand parents’ vaccine concerns. One such study involved focus groups with vaccine-hesitant mothers because mothers or other female guardians are the caregivers most often involved in their children’s health care decisions, according to Judith Mendel, MPH, of the U.S. Department of Health and Human Services.

Ms. Mendel’s study aimed to understand what drives vaccine-related confidence, how to overcome hesitancy over vaccines, and what messaging approaches might work most effectively. She and her colleagues recruited 61 women who participated in one of four groups in the Philadelphia area or one of four in the San Francisco area during April and May 2016. The women all were responsible for the health decisions of at least one child age 5 years or younger and had previously delayed or declined a recommended vaccine for their child.

Each group included six to nine women and involved a 2-hour semistructured discussion about health concerns; what vaccine confidence is; the mothers’ knowledge, attitudes, and beliefs about vaccines and immunization; and feedback on videos and info-graphics designed to educate others about immunization. The focus groups defined having confidence about vaccines as feeling trust, feeling good about a decision, having many years of research or practice, and being informed and knowledgeable.

“Three themes bubbled up together from the groups,” Ms. Mendel said. “Women had concerns about vaccine ingredients and their effects on physiology, about the recommended schedule, and about the medical system.”

Their concerns about vaccine ingredients and physiology would be familiar to pediatric providers:

• A persistent belief that autism is caused by vaccines.
• Concerns about vaccines made from weakened pathogens.
• Belief that vaccines replace a function that the body is equipped to handle on its own.
• Fears about short-term and long-term side effects.
• Little tolerance for established minor reactions to vaccines.

The mothers were accepting of the vaccines that had been on the schedule when they were children, such as polio, but they did not understand why vaccination starts so young and preferred “alternative” or catch-up schedules.

“They believed that when they were younger, the schedule started later,” Ms. Mendel said. “Some women felt there were too many injections given, while other women preferred not to use combination vaccines.”

Their concerns about the medical system, meanwhile, involved a general lack of trust for mainstream medicine and anyone involved in the immunization system. They believed that interactions with doctors today differ significantly from the way it was when they were children.

“They did not like feeling pressured by health care providers to vaccinate their kid,” Ms. Mendel said. “If they thought the provider was providing a somewhat authoritative or paternalistic stance with their recommendation, some of these women really shied from that and were dissuaded by that.”

What messages work?

The researchers then tested several messaging approaches with the women that included videos and printouts about vaccine safety, herd immunity, and how vaccines work. The materials received high ratings for being informative, coalescing around 4 on a Likert scale of 1-5, but “in terms of really swaying the needle on confidence, it was barely middle ground,” Ms. Mendel said, referring to scores ranging from 3.1 to 3.4.