The Moderating Effect of Vaccine Hesitancy on the Relationship between the COVID-19 Vaccine Coverage Index and Vaccine Coverage

Abstract

To examine COVID-19 vaccination barriers in the US, this study drew on publicly available county-level data (n = 3130) to investigate the impact of vaccine hesitancy on the relationship between county-level social/structural barriers and vaccine coverage. A hierarchical regression was performed to establish the relationship between the COVID-19 Vaccine Coverage Index (CVAC) and vaccine coverage, assess the moderating effect of vaccine hesitancy on this relationship, and explore the influence of ethno-racial composition on vaccine coverage. A significant, negative relationship (r2 = 0.11, f2 = 0.12) between CVAC and vaccine coverage by county was established (step 1). When vaccine hesitancy was introduced as a moderator (step 2), the model significantly explained additional variance in vaccine coverage (r2 = 0.21, f2 = 0.27). Simple slopes analysis indicated a significant interaction effect, whereby the CVAC–vaccine coverage relationship was stronger in low hesitancy counties as compared with high hesitancy counties. Counties with low social/structural barriers (CVAC) but high hesitancy were projected to have 14% lower vaccine coverage. When county-level ethno-racial composition was introduced (step 3), higher proportions of white residents in a county predicted decreased vaccination rates (p < 0.05). Findings indicate that CVAC should be paired with vaccine hesitancy measures to better predict vaccine uptake. Moreover, counties with higher proportions of white residents led to decreases in vaccine uptake, suggesting that future intervention strategies should also target whites to reach herd immunity. We conclude that public health leaders and practitioners should address both social/structural and psychological barriers to vaccination to maximize vaccine coverage, with a particular focus on vaccine hesitancy in communities with minimal social/structural barriers.

Understanding the determinants of vaccine hesitancy in the United States: A comparison of social surveys and social media

“…Most of these variables specifically apply to the uncertain model, while all models acknowledge the significance of the level of concern. Previous research has reported an association between vaccine uptake in hesitant communities and their level of apprehension regarding the accessibility and distribution of vaccines [ 111 , 112 ]. To this end, regions facing greater hurdles in distributing vaccines, as gauged by the multidimensional CVAC index of concern, tend to exhibit lower vaccination rates compared to regions with fewer obstacles [ 180 ].…”

“…Since no information is provided on the number of people or percentage of the population within each level of concern sub-category for social vulnerability, this data could not be transformed into a percentage value. Nonetheless, many studies have used this variable as a seminal measure to understand vaccine hesitancy (e.g., [ 111 , 112 ]); thus, the decision was made to keep it as a variable in this work.…”

Advancements in Vaccination Strategies: From Historical Milestones to Modern Innovations in Viral Disease Prevention and Public Health

“…Vaccine hesitancy refers to a situation where people either delay or refuse to get vaccinated, even when vaccines are accessible. (Tolley et al, 2023). There's a limited amount of research on strategies to combat vaccine hesitancy with a focus on influenza, HPV, childhood vaccines, diphtheria, tetanus, pertussis, and polio in the Americas.…”