Does the relative importance of MMR vaccine concerns differ by degree of parental vaccine hesitancy?: An exploratory study

Background: There has been a rise in the number of vaccine-hesitant parents (VHPs) in the US, many of whom express reservations about administering the MMR vaccine to their children. We studied the relative importance of attitudinal barriers to MMR vaccination among VHPs with differing levels of MMR vaccine-hesitancy.

Methods: We performed a cross-sectional exploratory analysis of a parental survey that assessed common vaccination barriers among MMR vaccine-hesitant parents in Michigan. The outcome of interest was parental MMR vaccination intention, measured on an 11-point scale, with higher numbers corresponding to greater intent. The relative importance of identified barriers to MMR vaccination was assessed across levels of vaccine hesitancy. Exploratory factor analysis was performed to identify underlying attitudinal constructs and assess if these constructs' importance varied depending on the degree of parental vaccine hesitancy.

Results: Our study population included 79 Michigan parents who initially screened positive for MMR vaccine-hesitancy. Within this sample, 47% of parents were unsure about their vaccination intentions and 20% expressed negative intentions, while a third (33%) of parents had positive vaccination intentions when further questioned. After grouping the barriers in our study into four underlying factors, parents with negative vaccination intentions had statistically significant higher factor score for the factor "risks versus benefits" and a statistically significant lower mean score for "vaccine importance," compared with parents with unsure or positive intentions.

Conclusions: In this exploratory study we found that vaccine-specific concerns have varying salience for parents based on their vaccination intention. Thus, future educational programs likely should tailor messages based on the degree of vaccine hesitancy expressed in their target populations in order to improve their overall effectiveness.