Pilot study to determine effect of an altruism intervention focusing on herd immunity to enhance influenza vaccination rates.

objectiveA prospective, single-arm clinical trial was conducted to evaluate an altruism-tailored educational intervention to improve parental attitudes and vaccine uptake in vaccine-hesitant parents.

methodsVaccine-hesitant parents at two primary care sites, spanning two influenza seasons from 2020 to 2021 were provided an intervention (spoken and written communication) which highlighted altruistic benefits of accepting the seasonal influenza vaccine to optimize herd immunity to help protect pediatric cancer patients. Eligible parents included those with children eligible for the seasonal influenza vaccine, those who were proficient in English, and those with scores on the adjusted Vaccine Hesitancy Scale (aVHS) suggesting vaccine hesitancy (score ≥ 3). Enrollees completed a demographic questionnaire, underwent the educational intervention, and repeated the aVHS. Vaccination status at that visit was assessed. The primary outcome was change in aVHS scores obtained pre- and post-intervention. Influenza vaccine acceptance, along with demographic information, were also analyzed.

resultsWe enrolled 510 parents of influenza vaccine eligible children and identified 73 vaccine-hesitant parents. There was an overall trend toward lower aVHS score, with a mean change in hesitancy score of -0.4 (P < 0.01). 43/73 (58.9 %) of the cohort experienced a positive effect toward a lower aVHS score, and 27/73 (37.0 %) of vaccine hesitant subjects became non-hesitant on the aVHS. Several demographic characteristics were associated with vaccine hesitancy in the screening population: educational level lower than bachelor's degree (p = 0.03), household income < 400 % of federal poverty level (p < 0.01), unmarried (p = 0.02), and identifying with a political affiliation other than Democrat (p < 0.01). However, no demographic characteristics were significantly associated with an individual becoming non-hesitant. Our altruism-tailored communication approach carried the largest positive impact on the altruism-specific question on the aVHS, decreasing the post-intervention response value by nearly 25 % (P < 0.01).

conclusionsOur altruism-tailored communication approach significantly improved attitudes regarding childhood influenza vaccine among vaccine-hesitant parents. CLINICALTRIALS: gov Identifier: NCT04568590.