according to a nationally representative survey.
Influenza vaccination hesitancy may be driven by concerns about vaccine effectiveness, researchers wrote in Pediatrics. These findings “underscore the importance of better communicating to providers and parents the effectiveness of influenza vaccines in reducing severity and morbidity from influenza, even in years when the vaccine has relatively low effectiveness,” noted Allison Kempe, MD, MPH, professor of pediatrics and director of the Adult and Child Consortium for Health Outcomes Research and Delivery Science at the University of Colorado at Denver, Aurora, and colleagues.
The World Health Organization considers vaccine hesitancy a leading threat to global health, but national data about vaccine hesitancy in the United States are limited. To assess hesitancy about routine childhood and influenza vaccinations and related factors, Dr. Kempe and colleagues surveyed more than 2,000 parents in February 2019.
The investigators used an online panel to survey a nationally representative sample of families with children aged between 6 months and 18 years. Parents completed a modified version of the Vaccine Hesitancy Scale, which measures confidence in and concerns about vaccines. Parents with an average score greater than 3 on the scale were considered hesitant.
Factors associated with vaccine hesitancy
Of 4,445 parents sampled, 2,176 completed the survey and 2,052 were eligible respondents. For routine childhood vaccines, the average score on the modified Vaccine Hesitancy Scale was 2 and the percentage of hesitant parents was 6%. For influenza vaccine, the average score was 2 and the percentage of hesitant parents was 26%.
Among hesitant parents, 68% had deferred or refused routine childhood vaccination, compared with 9% of nonhesitant parents (risk ratio, 8.0). For the influenza vaccine, 70% of hesitant parents had deferred or refused influenza vaccination for their child versus 10% of nonhesitant parents (RR, 7.0). Parents were more likely to strongly agree that routine childhood vaccines are effective, compared with the influenza vaccine (70% vs. 26%). “Hesitancy about influenza vaccination is largely driven by concerns about low vaccine effectiveness,” Dr. Kempe and associates wrote.
Although concern about serious side effects was the factor most associated with hesitancy, the percentage of parents who were strongly (12%) or somewhat (27%) concerned about serious side effects was the same for routine childhood vaccines and influenza vaccines. Other factors associated with hesitancy for both routine childhood vaccines and influenza vaccines included lower educational level and household income less than 400% of the federal poverty level.
The survey data may be subject to reporting bias based on social desirability, the authors noted. In addition, the exclusion of infants younger than 6 months may have resulted in an underestimate of hesitancy.
“Although influenza vaccine could be included as a ‘routine’ vaccine, in that it is recommended yearly, we hypothesized that parents view it differently from other childhood vaccines because each year it needs to be given again, its content and effectiveness vary, and it addresses a disease that is often perceived as minor, compared with other childhood diseases,” Dr. Kempe and colleagues wrote. Interventions to counter hesitancy have “a surprising lack of evidence,” and “more work needs to be done to develop methods that are practical and effective for convincing vaccine-hesitant parents to vaccinate.”
Logical next step
“From the pragmatic standpoint of improving immunization rates and disease control, determining the correct evidence-based messaging to counter these perceptions is the next logical step,” Annabelle de St. Maurice, MD, MPH, an assistant professor of pediatrics in the division of infectious diseases at University of California, Los Angeles, and Kathryn Edwards, MD, a professor of pediatrics and director of the vaccine research program at Vanderbilt University, Nashville, wrote in an accompanying editorial.
“Communications should be focused on the burden of influenza in children, rebranding influenza vaccine as a ‘routine’ childhood immunization, reassurance on influenza vaccine safety, and discussion of the efficacy of influenza vaccine in preventing severe disease,” they wrote. “Even in the years when there is a poor match, the vaccine is impactful.”
The research was supported by the National Institutes of Health. Two study authors disclosed financial ties to Sanofi Pasteur, with one also disclosing financial ties to Merck, for work related to vaccinations. The remaining investigators had no relevant financial disclosures. Dr. de St. Maurice indicated that she had no relevant financial disclosures. Dr. Edwards disclosed grants from the Centers for Disease Control and Prevention and the NIH; consulting for Merck, Bionet, and IBM; and serving on data safety and monitoring boards for Sanofi, X4 Pharmaceuticals, Seqirus, Moderna, and Pfizer.
SOURCE: Kempe A et al. Pediatrics. 2020 Jun 15. doi: 10.1542/peds.2019-3852.