Counties Most Vulnerable to COVID Have Been the Slowest to Vaccinate Medics transfer a patient on a stretcher from an ambulance outside the Coral Gables Hospital where COVID-19 patients are treated in Coral Gables near Miami, Florida, on July 30, 2020. CHANDAN KHANNA / AFP via Getty Images By A ProPublica analysis of county data maintained by the U.S. Centers for Disease Control and Prevention shows that early attempts to prioritize people with chronic illnesses like heart disease, diabetes and obesity have faltered. At the same time, healthier — and often wealthier — counties moved faster in vaccinating residents, especially those 65 and older. (Seniors are a more reliable measure of vaccination progress than younger adults, who are less likely to have been eligible long enough to receive their second shots.) Counties with high levels of chronic illnesses or “comorbidities” had, on average, immunized 57% of their seniors by April 25, compared to 65% of seniors in counties with the lowest comorbidity risk.