Vaccine Acceptance

Patterns of Vaccine Uptake

Evaluating how and when populations utilize available vaccines is critical to identifying gaps in current healthcare systems. Research led by Emory investigators underscores that absolute coverage metrics only tell part of the story; timeliness and adherence to clinical schedules are equally vital indicators of systemic public health strength. Previous research conducted by members of the Vaccine Policy Program found that 37% of US children were not fully adherent to the published vaccine schedule, indicating potential additional issues with vaccine hesitancy and logistical access to vaccines that may not be captured in standard metrics 

Longitudinal analyses reveal significant complexities in the implementation of early childhood immunization schedules. While overall long-term coverage may remain high, compliance with the exact intervals recommended by the Advisory Committee on Immunization Practices (ACIP) varies significantly by sociodemographic disparities by race/ethnicity and poverty status. This directly impacts the up-to-date status by 19 to 35 months of age, who showed notable declines in adherence in 2021 compared to 2020. Recent temporal trends similarly indicate that varying vaccination schedules can delay critical early childhood protections, creating temporary windows of vulnerability to vaccine-preventable diseases. However, progress has been made. From 2011 to 2021, adherence to the recommended schedule increased from 35.7% to 52.2%, and adherence to the alternate schedule decreased from 28.2% to 15.1%. Correspondingly, the proportion of children who were not up-to-date declined substantially over the same period, from 49.0% to 33.3%. Together, these trends suggest a shift among young children away from delayed, alternate immunization patterns and toward closer adherence to the recommended schedule, even as roughly one in three children remained behind on recommended vaccinations by 2021. 

Understanding Vaccine Hesitancy

Vaccine hesitancy is not a uniform phenomenon; it exists on a continuum and is often highly specific to distinct vaccine types, legal exemptions, and demographic subgroups. Our work aims to deconstruct these specific misperceptions to arm healthcare providers with evidence-based communication tools.  

Adolescent Vaccinations + Misinformation:  A prominent focus is overcoming behavioral and informational barriers to the Human Papillomavirus (HPV) vaccine. Adolescent HPV vaccine uptake consistently lags behind that of other routine adolescent immunizations. In 2017, series completion stood at just 49% compared to 88% for Tdap, driven in large part by widespread parental misconceptions about safety and necessity.  

To bridge these gaps, our work aligns closely with collaborative, multi-sector initiatives dedicated to optimizing the policy and programmatic environment for HPV vaccination and cancer prevention. This includes sustained engagement with state-, region- and national-level roundtables, such as HPV Cancer Free GA, the HPV Vaccination Roundtable of the Southeast(where the Steering Committee is currently chaired by Dr. Bednarczyk), and the National HPV Vaccination Roundtable. Through these partnerships, we have engaged on key topics such as starting HPV vaccination at age 9 and supporting state-level cervical cancer elimination efforts.  

We have directly addressed these barriers, cataloguing the most common HPV vaccine myths encountered in clinical practice and equipping providers with practical, evidence-based responses to concerns such as false safety attributions, the misbelief that natural clearance renders vaccination unnecessary, and the misconception that Pap smear screening eliminates the need for early vaccination.  

We have also worked to deepen understanding of the hesitancy landscape itself, recognizing that parental hesitancy toward HPV vaccination exists on a spectrum rather than as a binary state, and that different levels of hesitancy reflect distinct underlying concerns requiring differentiated communication strategies.  

Taken together, this work underscores that a robust, tailored provider recommendation, one that accounts for the specific nature and intensity of a parent's hesitancy, remains among the most effective tools for neutralizing resistance and improving HPV vaccine uptake.  

Systemic Hesitancy + The Impact of Declining Vaccine Coverage:  Beyond vaccine-specific concerns, vaccine hesitancy often manifests as a broader, systemic issue intricately tied to individual morals, ideological beliefs, and political dynamics. Research led by Emory investigators demonstrates that conventional public health messaging strictly focused on “care and harm” may not resonate with hesitant populations. Instead, high levels of vaccine hesitancy are strongly correlated with individual endorsements of “purity” and “liberty” values, suggesting that future communication strategies must be broadened to align with these foundational worldviews. When these deeper behavioral values translate into action, they often lead to the exploitation of legal frameworks.  

Declines in vaccine coverage is not just an abstract health policy issue. This carrise quantifiable, real-world consequences for community health, which is precisely what the VaxImpactMap project is designed to illustrate. The VaxImpactMapproject at Emory is an interactive tool for quantifying the health and economic costs of declining childhood vaccination. It lets users select a vaccine-preventable disease, hover over a state to see projected impacts, and adjust a slider to model different magnitudes of coverage decline, showing additional cases, hospitalizations, deaths, workdays lost, and productivity/hospitalization costs for rotavirus, pertussis, and pneumococcal disease. It’s positioned as a resource for public health departments, journalists, and advocacy organizations.  

This multi-level work heavily explores strengthening delivery infrastructure at both macro and micro levels. On the global stage, we investigate the targeted use of digital logistics networks and community-embedded health workers to eliminate missed opportunities for vaccination. Domestically, this operational research is paired with deep analytical partnerships across Emory’s ecosystem. Through the Emory Alliance for Vaccine Epidemiology (EAVE), we help drive high-impact epidemiological research targeting vaccine evaluation, pathogens dynamics, and the precise tracking of vaccine uptake. Furthermore, our collaboration with the CDC-funded Center for Infectious Disease Modeling and Analytics & Training Hub (CIDMATH) enables the integration of advanced infectious disease modeling, predictive analytics, and wastewater surveillance data into actionable policy frameworks, ensuring that delivery strategies are backed by real-time situational awareness. 

The structural dangers of these localized immunity gaps have been extensively studied by EVC Policy Director Dr. Bednarczyk, particularly with regard to measles. Previous research documented gaps in population-level protection against measles among children and adolescents younger than 18 in the US, with updated data and models highlighting the potential impact of the COVID-19 pandemic on measles vaccine coverage.  Considering these findings and general issues with vaccine confidence, Dr. Bednarczyk documented critical systemic gaps in national measles vaccine coverage in a 2025 report published in Public Health Reports. This report warned that lingering catch-up vaccination deficits from the COVID-19 pandemic and a lack of substate-level surveillance were quietly expanding the pool of susceptible children, leaving the US vulnerable to large measles outbreaks. His commentary chillingly predated the massive domestic resurgence that began just weeks later. 

Dr. Bednarczyk summarized the history and current status of vaccine hesitancy in a 2026 publication, providing a readily-available reference on the issues and potential paths forward to address these concerns.