VaxImpact – Quantifying the Health and Economic Costs of Declining Childhood Vaccination

Introduction

Childhood vaccination rates in the United States have declined in recent years. Growing confusion about vaccine safety and changes to public health guidance may accelerate these declines, putting more children at risk for preventable diseases.

VaxImpact is an interactive tool that projects the real-world consequences of reduced vaccine coverage. Using epidemiological models and state-level data, it estimates the additional disease burden—cases, hospitalizations, deaths, missed workdays, and healthcare costs—that would result from specific declines in immunization coverage.

This tool is designed for public health officials, policymakers, journalists, and parents who need evidence-based projections to inform decisions, communicate risks, and support vaccination programs.

Explore VaxImpact to see how coverage declines translate into health and economic impacts in your state.

    Using VaxImpact

    How to navigate the tool:

    1. Select a vaccine-preventable disease from the dropdown menu
    2. Hover over any state to view projected impacts specific to that location
    3. Adjust the slider to model different magnitudes of coverage decline (e.g., 5%, 10%, 15% reduction)
    4. Choose your outcome:
      • Additional burden (default): Increase above current levels due to declining coverage
      • Total burden: Combined current and additional disease burden
    5. Choose your scale:
      • Per capita (default): Results are normalized by the number of children at risk in each state (useful for comparing risk intensity across states)
      • Absolute numbers: Total projected cases, hospitalizations, and deaths (useful for understanding overall burden)
    Understanding the Metrics

    Additional cases
    The projected annual increase in children with the disease, resulting from reduced vaccination of newborns.

    Additional hospitalizations
    The number of additional cases severe enough to require inpatient hospital care.

    Additional deaths
    Estimated annual increase in deaths attributable to the disease, based on historical case-fatality rates.

    Additional days of work missed
    Projected increase in workdays lost annually as caregivers stay home to care for sick children.

    Additional economic costs
    Combined annual costs in US dollars, including direct medical expenses (hospitalizations, treatments) and indirect costs (lost productivity from missed work).

    Interpreting the Results

    What these projections represent:

    The estimates model the steady-state impact of sustained lower vaccination coverage—the annual disease burden expected once reduced immunization rates become established across the population. These are not outbreak scenarios or one-time events.

    The model assumes coverage declines affect newborns beginning now, with impacts accumulating as these cohorts age through childhood. Results reflect long-term equilibrium conditions.

    Key considerations:

    • Even modest coverage declines (5-10%) can produce substantial increases in disease burden, particularly in populous states or those with higher birth rates
    • Geographic variation in existing coverage levels means some states face higher baseline risk than others
    • Declines are not evenly distributed—communities with lower vaccination rates experience disproportionate impacts
    • These projections use conservative assumptions; outbreaks could produce more severe short-term spikes
    Methodology

    VaxImpact uses simple analytical epidemiological models calibrated to current state-level vaccination coverage, birth rates, and disease surveillance data. The models are based on the idea that declines in coverage will only affect new births. Older children who were vaccinated as babies retain the immunity conferred by immunization.  Therefore, gaps in immunity take time to accrue. 

    Disease parameters (transmission rates, severity, case-fatality ratios) are derived from CDC surveillance, published literature, and historical outbreak data. Economic costs include direct medical expenses and indirect productivity losses, calculated using standard health economics methods.

    For detailed technical documentation, including data sources, model equations, parameter values, and validation procedures, see:
    VaxImpact Technical Methods

    Use Cases

    For public health departments:
    Project disease resurgence in your state under different coverage scenarios to inform resource planning and intervention priorities.

    For journalists and media:
    Access state-specific, evidence-based estimates to illustrate the concrete consequences of vaccine hesitancy for your audience.

    For advocacy organizations:
    Use data-driven projections to demonstrate the importance of maintaining high vaccination coverage and to support policy recommendations.