The effect of screening for vaccine hesitancy on the subsequent development of hesitancy: a randomized controlled trial, Houston, TX

Vaccine hesitancy remains a global health threat. Addressing parental vaccine hesitancy is essential to maintaining high vaccine coverage levels and preventing disease outbreaks; however, it is unknown if administering a vaccine hesitancy screening tool negatively impacts parental vaccine beliefs. We conducted a stratified randomized controlled trial in pediatric primary care practices. English-speaking parents ≥18 years of age seeking routine care for infants <3 months of age were eligible. Participants were randomized to receive 1 of 2 surveys - the Parent Attitudes about Childhood Vaccines (PACV) survey or a placebo survey. Six months after initial enrollment, all participants were asked to complete the PACV, regardless of initial randomization group. Our primary outcome was the proportion of hesitant to non-hesitant parents at 6-months between randomization groups. We examined associations between vaccine hesitancy and participant characteristics. We also evaluated the change in the proportion of vaccine-hesitant parents in the PACV group between baseline and 6-month follow up. We enrolled 1705 parents at baseline. At 6-month follow up, 819 parents completed the PACV (50.2% from PACV group vs. 54.1% from placebo group). The proportion of hesitant parents at 6 months did not differ between PACV and placebo groups (6.6% vs. 6.1%; p = .78) and the odds of hesitancy among PACV group participants was not higher than those in the placebo group (OR = 1.10; 95% CI: 0.63-1.93; p = .743). Race was the only characteristic significantly associated with vaccine hesitancy at 6-month follow up (p = .003). Overall, administration of the PACV did not trigger vaccine hesitancy in this study population.