County-Level COVID-19 Modeling Results for North Carolina

Disclaimer: Simulation models represent our best understanding of complex real-world phenomena. This model is based on a prior influenza model, and is updated to reflect emerging peer-reviewed literature and local data, including from the census, Safegraph (mobility data), Facebook mask usage data, and COVID data from NCDHHS. Results in this presentation are based on a version of the model that was calibrated using reported lab-confirmed COVID cases and deaths from the NCDHHS through February 15, 2021. 

Like all models, simplifying assumptions are made. Model assumptions capture many aspects known to affect COVID trends, such as the structure of interactions within and across communities and nuanced human behavioral responses – though not all. We continue to iterate this model as we learn about important factors, or as COVID context evolves (e.g., as variant dominance shifts and transmissibility changes, new vaccines become available). Data from the Behavioral Risk Factor Surveillance System is used to estimate the distribution of individuals by race, age, and comorbidity status. We also used U.S. Census tract-level data to estimate the size of households (1 to 6 people), whether or not children were present in the household, and the race/ethnicity of the household. Also of note, these county-level analyses presented here are subject to greater uncertainty than state-level estimates, due to smaller population size. The current figures do not report the uncertainty intervals for these estimates.

The models and results shown on this website refer to the following article: https://jamanetwork.com/journals/jamanetworkopen/fullarticle/2780539

COVID-19 infections, hospitalizations, and deaths were modeled with 4 different behavioral and policy interventions:

  1. Non-pharmaceutical interventions (NPIs) (includes masks, social distancing, etc…)
    1. NPI Maintained: 
      1. Mask usage and social distancing remain at pre-vaccination levels: 70% mask usage, 15% voluntary isolation and self-quarantine. Community and workplace interaction remain reduced. 
    2. NPI Removed:  
      1. March 27th: Workplace and community interaction including schooling return to normal, agents no longer isolate or quarantine immediately.
      2. Face mask usage decreases at a rate proportional to the number of agents vaccinated until the end of the vaccine distribution. 
  2. Vaccine Efficacy (percent of those vaccinated protected from infection)
    1. High: 90%
    2. Low: 50%
  3. Vaccine Rollout Speed (duration over which adults are vaccinated)
    1. Fast: Gradual rollout from Dec 27th to April 6th
    2. Slow: Gradual rollout from Dec 27th to June 25th
  4. Vaccine Coverage (percent of adults vaccinated by end of rollout)
    1. Med: By April 6th (fast rollout) or June 25th (slow rollout), coverage reaches 50% of adults.
    2. Low: By April 6th (fast rollout) or June 25th (slow rollout), coverage reaches 25% of adults.

Compare daily new infections between counties for a specific scenario

The following interactive graph illustrates the daily new infections between different counties in North Carolina using a specific set of parameters.

Use the drop down menu to turn “on” scenarios to compare daily new infections. Note that the y-axis scale may change to allow you to better see differences. Check out Tableau functions at the bottom of the window. You can reset the original scenarios using the reset button . You can also download the graph into different types of files, including images and datasets.

Try comparing your county to other counties:

1. Select values for NPIs and vaccine efficacy, coverage, and rollout speed.

2. Check your county from the drop-down list as well as other counties to which to compare.

Compare daily new infections between scenarios for a specific county

The following interactive graph illustrates the daily new infections using a variety of parameter combinations for a specific county in North Carolina.

Compare cumulative infections between counties or regions* for a specific scenario

The following interactive graph illustrates the cumulative infections between different counties/regions in North Carolina using a specific set of parameters.

Compare cumulative infections between scenarios for a specific county or region*

The following interactive graph illustrates the cumulative infections using a variety of parameter combinations for a specific county/region in North Carolina.

*NC Regions

Region 1Region 2Region 3Region 4Region 5Region 6Region 7Region 8Region 9Region 10
CherokeeBuncombeDavidsonAlexanderAlamanceAnsonEdgecombeBladenBertieBeaufort
ClayBurkeDavieCabarrusCaswellCumberlandFranklinBrunswickDareCarteret
GrahamCaldwellForsythCatawbaChathamHarnettGranvilleColumbusHydeCraven
HaywoodHendersonStokesClevelandDurhamHokeHalifaxDuplinMartinGreene
Jackson MadisonSurryGastonGuilfordLeeJohnstonNew HanoverNorthamptonJones
MaconPolkWataugaIredellOrangeMontgomeryNashOnslowWashingtonLenoir
SwainRutherfordWilkesLincolnPersonMooreWakePenderTyrrellPamlico
TransylvaniaYanceyYadkinMecklenbergRandolphRichmondWarrenPenderHertfordPitt
AveryAlleghanyRowanRockinghamScotlandWilsonRobesonPerquimansWayne
MitchellAsheStanlyVanceSampsonGates
McDowellUnionCurrituck
Chowan
Camben