COVID-19 vaccinations associated with reduction of COVID-19 infections and deaths among Medicare beneficiaries

By Colin Lightfoot, M.Sc. Infection and ImmunityReviewed by Danielle Ellis, B.Sc.Oct 7 2021

Coronavirus disease 2019 (COVID-19) vaccinations were introduced in the United States in December 2020. Initially, COVID-19 vaccines were made available to nursing home residents and healthcare workers but were then rolled out differently according to state, but mainly prioritizing the elderly.

Study: Associations Between County-level Vaccination Rates and COVID-19 Outcomes Among Medicare Beneficiaries. Image Credit: CameraCraft/ Shutterstock

The first vaccine types to be rolled out were the Pfizer and Moderna in December, of which two doses were required, several weeks apart. Following these, the Johnson and Johnson vaccine was made available in February 2021, which only requires a single dose.

The high efficacy of these vaccines was shown in the initial clinical trials in preventing severe COVID-19 and continued protection against emerging severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) variants. However, the effectiveness could be slightly lower.

The authors of a study available on ASPE* identified the associations between COVID-19 infections, hospitalizations, and deaths among Medicare fee-for-service (FFS) beneficiaries and the fully vaccinated population at the county-level between January and May 2021.

The associations between cumulative county-level COVID-19 vaccination rates and the risk of COVID-19

When the COVID-19 vaccinations were first rolled out, weekly vaccination rates in January were less than 1% for the age groups 18-64 and 65+, but by the last week of May, the rates increased to a total of 47% and 80%.

Considering the risk of COVID-19 infection, among individuals who were 65 or older, a 10% increase in the COVID-19 vaccination rate was associated with an 11% decrease in the chance of infection, with an estimated reduction between 9-12%. For those aged between 18 and 64, a 10% increase in vaccinations was associated with approximately an 11% and 12% decrease in the odds of hospitalizations and deaths due to COVID-19.

What was the impact of COVID-19 vaccines on demographic subgroups?

Among Medicare beneficiaries, the rates of COVID-19 vaccinations were associated with an estimated 17-21% reduction in infections and an estimated 21-25% reduction in deaths across ethnic and racial groups.

Alaska Natives and American Indians displayed the largest reduction, with an estimated reduction in infections of 21% and a reduction in deaths of 25%, compared to 18% and 22% among White beneficiaries. White beneficiaries accounted for the largest estimated number of reductions in COVID-19 outcomes, who made up 81% of the study cohort.

Among Black beneficiaries, the authors estimated reductions of 29,000 infections and almost 4,600 deaths in the Medicare population, 29.000 infection and almost 5,000 death reductions in Hispanic beneficiaries, almost 7,600 infection and 1,400 reductions in Asian beneficiaries, and reductions of 2,000 infections and 400 deaths in Alaska Native and American Indian beneficiaries within the Medicare population.

What was the impact of COVID-19 vaccines on nursing home residents?

Long-term nursing home residents are a group of individuals at a significantly high risk of serious health complications and death if they become infected with SARS-CoV-2. They are disproportionally affected by COVID-19.

For long-term nursing home residents, vaccine administration was associated with estimated reductions of almost 8,400 infections, 1,900 hospitalizations, and 2,200 deaths within the cohort study. When projected to the total Medicare population, it translates to an estimated reduction of almost all 21,000 infections, 4,900 hospitalizations, and 5,600 deaths.

In comparison to community-based beneficiaries, long-term nursing home residents were less likely to be hospitalized, but this may be due to them already residing in a healthcare setting.

Implications

This study shows that among the Medicare population in early 2021, COVID-19 vaccinations were associated with thousands of fewer deaths. This was displayed via population-level regression-based estimates and is consistent with the evidence on the clinical effectiveness of the vaccines. The authors hypothesize that more Medicare beneficiaries are expected to be saved from hospitalizations and deaths related to COVID-19 as cumulative vaccination rates continue to rise.

Notice

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