Vaccination is Local: COVID-19 Vaccination Rates Vary by County and Key Characteristics

introduction

COVID-19 has disproportionately affected certain underserved and high-risk populations, including those of color, those with underlying health conditions, and those with socio-economic disadvantage. Ensuring access to COVID-19 vaccines for these communities can help combat the diverse health effects of the virus and achieve herd immunity. The Biden administration has prioritized vaccine equity as a priority, but states and local jurisdictions differ in how and to what extent they prioritize equity. Given that vaccine adoption in the U.S. is inherently local, understanding how vaccination rates differ at the local level is important to educate public relations and promote justice. Previous CDC analysis found that counties with high social vulnerability had lower vaccination rates than counties with low social vulnerability as of early March.

This short edition builds on this analysis by analyzing how vaccination rates differ from one county to the next and identifying key features of the county that are associated with higher or lower count vaccination rates. It is based on the KFF analysis of newly available data from the Centers for Disease Control and Prevention (CDC), which shows what percentage of the population at the county level is fully vaccinated. The data also offer this proportion for people aged 65 and over. The CDC data, while incomplete (see Methods), provide the first comprehensive data to investigate vaccine adoption at the county level. The results of this brief usage data from March 29, 2021 cover 72% of all counties (2,247) in the United States. For more information on the data, the measures included in the analysis and the methodology, see the Methods field.

Main results

There are large variations in reported vaccination rates by county in the United States. In the 2,247 counties included in this analysis, the average vaccination rate is 15.8% for the general population and 46.7% for the population aged 65 and over. Seven of the ten countries with the highest vaccination rates are in Alaska, where 21.9% of the population will be fully vaccinated as of March 28, 2021 (Table 1). Alaska was consistently at or near the top of the states as measured by the percentage of the fully vaccinated population.

There are mixed results on how the county's vaccination rates align with national prioritization recommendations and state prioritization decisions. The CDC recommended prioritizing certain groups for access to vaccines while vaccine supplies are limited, including health professionals and long-term care residents, as well as older adults and those with conditions who are at greater risk of developing severe COVID-19 disease. In addition to health workers and long-term care residents, all states have given priority to vaccinating older adults, and in fact counties with a higher proportion of people 65 and over have higher vaccination rates (18.2%) than counties with a lower one Proportion of people aged 65 and over (14.9%). In contrast, most states were slower to open eligibility to those with high-risk conditions, and the list of qualifying conditions differs between states. We found that districts with a higher proportion of people with certain high-risk diseases had a lower average vaccination rate than districts with a lower proportion (14.0% versus 16.7%), suggesting that those who the greatest risk of severe COVID-19 may be less likely to have been reached so far.

Additionally, the county's vaccination rates don't appear to be directly correlated to the effects of COVID-19. Districts with low levels of community transmission of COVID-19 and lower levels of COVID-19 deaths per 100,000 people have higher vaccination rates than districts with high levels of community transmission and mortality. The CDC defines community transmission rates for counties based on cases per 100,000 residents and percentages of positive tests in the past week. Counties with "low" community transmission rates (and thus fewer cases and positive tests) have an average vaccination rate of 18.3%, compared to 15.7% in counties with "high" community transmission rates. In the counties with the lowest cumulative deaths per 100,000 people, the average vaccination rate is 16.8%, compared with 15.9% in the counties with the highest deaths per 100,000 people.

Counties with higher proportions of blacks and Hispanics have lower vaccination rates than counties with lower proportions. In counties with a high percentage of blacks, the vaccination rate is 13.7% compared to 16.4% in counties with a low percentage of blacks. There is less difference in vaccination rate between counties with high and low Hispanic populations, with the vaccination rate in counties with higher Hispanic populations being 15.0% versus 15.9% in counties with low Hispanic populations amounts to. These results are consistent with lower vaccination rates among blacks and Hispanics overall. While the gap in vaccination rates for Hispanic Americans is disappearing in the age 65+ population, it remains for blacks. The average vaccination rate for people 65 and older is the same in countries with high and low Hispanic Americans (46.7%). However, like vaccination rates for the general population, vaccination rates for people aged 65 and over are lower in high-black countries than in low-black countries (44.6% versus 47.3%).

In addition, there are higher uninsured rates and poverty rates in the district associated with lower vaccination rates. The average vaccination rate in countries with relatively high non-insurance rates is 15.3% compared to 17.1% in countries with lower non-insurance rates. Higher poverty rates, which are associated with inadequate insurance coverage and can contribute to other barriers to access to vaccines, are also associated with lower vaccination rates in the county (Appendix table).

In accordance with the recent CDC researchDistricts ranked high in the Social Vulnerability Index (SVI) (those with higher vulnerability) have lower vaccination rates than districts ranked lower in this index (14.1% versus 17.7%). This finding is not surprising as SVI aggregates measurements of socioeconomic status, age, race / ethnicity, some of which were discussed above, as well as additional measurements of disability, dwelling type, and transport access. Regardless, people in countries with higher susceptibility are currently less likely to be vaccinated than people in countries with lower susceptibility.

Metro counties have lower vaccination rates for the general population than non-Metro counties, and vaccination rates are lower in counties that voted for Trump than those that voted for Biden. The proportion of the total population vaccinated in metro districts is 15.1% versus 16.3% in non-metro districts. However, the proportion of the vaccinated population aged 65 and over is higher in metro districts, 47.5% versus 46.3% in non-metro districts. Additionally, the average vaccination rate in counties that voted for Trump is 15.5%, compared to 16.3% in counties that voted for Biden.

Conclusion

This analysis of vaccination rates at the district level provides further evidence of inequalities in previous COVID-19 vaccination efforts. Districts with higher proportions of people disproportionately affected by COVID-19, including blacks and Hispanic Americans, people at high risk, and people living in poverty, have lower vaccination rates than districts with lower proportions of these populations. This data can be used to guide further public relations and vaccination efforts in the future. In addition, we note that districts with higher levels of transmission of COVID-19 in the community have lower vaccination rates, suggesting that efforts to speed up vaccination and stave off rising cases could be more targeted in some areas.

In this summary, data is analyzed at the district level and obtained from several sources.

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Our key finding, vaccination rates by county, was obtained from the Centers for Disease Control and Prevention (CDC )’s COVID-19 Integrated County View. The CDC data shows that vaccination rates are complete for the general population and those over 65 years of age. No data is reported for Hawaii, New Mexico, Texas, and California's smallest counties. Additionally, we're excluding data for counties where less than 80% of vaccination records include the district of residence, eliminating data for Colorado, Georgia, Nebraska, New Hampshire, South Dakota, Vermont, Virginia, and West Virginia. The analysis includes data for 2,247 counties, 72% of the total counties in the US.

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We also use the CDC data for the Community Transmission Level, which classifies districts based on new cases per 100,000 people and the percentage of positive tests in the last 7 days.

Data on the categorization of counties according to demographic characteristics of the population comes from the 5-year estimates of the American community survey of the Census Bureau 2019 by counties. We use ACS data to categorize counties based on age, race / ethnicity, poverty, and health insurance of residents. Specifically, we calculate the proportion of the county population aged 65 and over, colored, non-Hispanic blacks, and Hispanics in a family with income below poverty and no insurance.

Data on the cases and deaths was extracted from data from the Johns Hopkins University county on March 28, 2021. To calculate cases / deaths per 100,000 population, the totals for each county were drawn from demographic data from the Census Bureau – using the total population.

The 2020 presidential election results were pulled from a GitHub repository, which compiled data from media sources such as The Guardian, townhall.com, Fox News, Politico and the New York Times. Alaska is excluded from this component of the analysis because the only data available is at the district level and cannot be extrapolated to counties.

Subway and non-subway classifications are based on the US Department of Agriculture's 2013 Rural-Urban Continuum Codes. Districts with codes 1 to 3 are classified as "subway" and 4 to 9 as "non-subway".

Data on the proportion of the population with underlying diseases that put them at higher risk of severe COVID-19 illnesses according to counties comes from the CDC. The conditions included chronic kidney disease, COPD, heart disease, diagnosed diabetes, and obesity (BMI> = 30).

The County Social Vulnerability Index (SVI) is from the CDC Agency for the Register of Toxic Substances and Diseases. SVI indicates a community's vulnerability due to certain social conditions (i.e. socio-economic status, household composition, language, etc.) that can affect the community in the event of a disaster.

To classify counties, we translate continuous key figures into categorical results based on the following group definitions:

For continuous measurements of age, poverty rate, non-insurance rate, high-risk illness, SVI, and cases and deaths per 100,000, we have rated districts below the 25th percentile of the total distribution of districts as "low" for each measurement and 75th percentile as "high" and all other counties as "medium". Specific breaks for each variable are given in Appendix Table 1.
For continuous measurements of race / ethnicity, we classify counties in which the proportion of residents of each race / ethnic group is above or below the national average of the population distribution for that group as “high” or “low”. In particular, we have defined “high proportion of colored people” as rural districts in which more than 40% of the population are colored. “High Proportion Black People” as counties where more than 12% of the population are Black and non-Hispanic; and "High percentage Hispanic" as counties where more than 19% of the population are Hispanic.