CDC study: Vulnerable populations saw lower rates of COVID-19 vaccinations as eligibility expanded

Socially vulnerable populations saw lower rates of COVID-19 vaccination coverage, even as eligibility for the shots expanded, according to a Centers for Disease Control and Prevention (CDC) study released on Friday.

The CDC determined that between Dec. 14 and May 1, inequities in vaccination coverage persisted and grew in counties with more socially vulnerable populations, particularly in rural and “large fringe metropolitan,” or suburban, counties.

The CDC’s research confirmed suspicions that counties with vulnerable populations were more likely to have lower vaccination rates compared to other counties, indicating the need for further attention in the vaccination effort.

For the study, the agency used its 2018 social vulnerability index data to distribute the counties into four groups, with the first quartile being the least vulnerable counties and the fourth being the most. The study defined vaccination coverage as the number of adults who had received at least one COVID-19 vaccine dose out of the total county population. 

The data showed that overall, counties considered the least vulnerable had 59.3 percent vaccination coverage, compared to the more vulnerable counties that had 49 percent coverage. 

The difference was more visible in large fringe metropolitan counties and rural counties, where there was a 16.7 percentage-point difference and 12.3 percentage-point difference between the most and least vulnerable groups, respectively. 

Counties with lower socioeconomic status also had lower vaccination coverage, with a 16.7 percentage-point difference between the groups with the highest and lowest socioeconomic status. 

Areas with higher percentages of households with children, single parents and persons with disabilities saw lower vaccination coverage as well, with an 18.1 percentage-point difference from counties with the lowest percentages of these households.

Vaccination rates have decreased in the country after the most eager people have already gotten their shots, prompting officials to turn their attention to trying to improve access and offering incentives to increase turnout. 

This CDC research suggests officials should conduct more outreach to more vulnerable counties and populations, including setting up local mobile and walk-in clinics, using trusted local voices and organizing home visits for those who need it. 

The study analyzed data from adults in 3,129 counties, or 99 percent of U.S. counties, leaving out California counties with populations less than 20,000 and all Hawaii counties due to a lack of available county-level data. 

The data is as of May 1, after all people 16 and older had eligibility to get the vaccine. At the time 54 percent of adults in those counties had received at least one dose.