A modeling study led by Centers for Disease Control and Prevention (CDC) researchers estimates that COVID-19 vaccination averted 27 million infections, 1.6 million hospitalizations, and 235,000 deaths among US adults from December 2020 to September 2021.

In the study, published yesterday in JAMA Network Open, the researchers extrapolated the number of COVID-19 infections and deaths from hospitalization data from Dec 1, 2020, to Sep 30, 2021. Then they combined the estimates with data on vaccine uptake and effectiveness to estimate the risk of infection, hospitalization, and death.

Vaccination was considered two doses of the Pfizer/BioNTech or Moderna vaccine or one dose of the Johnson & Johnson version.