Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
. 2022 Jul 1;5(7):e2220385.
doi: 10.1001/jamanetworkopen.2022.20385.

Estimated Number of COVID-19 Infections, Hospitalizations, and Deaths Prevented Among Vaccinated Persons in the US, December 2020 to September 2021

Molly K Steele  1   2 , Alexia Couture  1   3 , Carrie Reed  1   3 , Danielle Iuliano  1   3   4 , Michael Whitaker  1   2 , Hannah Fast  1   5 , Aron J Hall  1   2 , Adam MacNeil  1   2 , Betsy Cadwell  1   2 , Kristin J Marks  1   4   6   7 , Benjamin J Silk  1   2   4
Affiliations

Estimated Number of COVID-19 Infections, Hospitalizations, and Deaths Prevented Among Vaccinated Persons in the US, December 2020 to September 2021

Molly K Steele et al. JAMA Netw Open. .

Abstract

Importance: The number of SARS-CoV-2 infections and COVID-19-associated hospitalizations and deaths prevented among vaccinated persons, independent of the effect of reduced transmission, is a key measure of vaccine impact.

Objective: To estimate the number of SARS-CoV-2 infections and COVID-19-associated hospitalizations and deaths prevented among vaccinated adults in the US.

Design, setting, and participants: In this modeling study, a multiplier model was used to extrapolate the number of SARS-CoV-2 infections and COVID-19-associated deaths from data on the number of COVID-19-associated hospitalizations stratified by state, month, and age group (18-49, 50-64, and ≥65 years) in the US from December 1, 2020, to September 30, 2021. These estimates were combined with data on vaccine coverage and effectiveness to estimate the risks of infections, hospitalizations, and deaths. Risks were applied to the US population 18 years or older to estimate the expected burden in that population without vaccination. The estimated burden in the US population 18 years or older given observed levels of vaccination was subtracted from the expected burden in the US population 18 years or older without vaccination (ie, counterfactual) to estimate the impact of vaccination among vaccinated persons.

Exposures: Completion of the COVID-19 vaccination course, defined as 2 doses of messenger RNA (BNT162b2 or mRNA-1273) vaccines or 1 dose of JNJ-78436735 vaccine.

Main outcomes and measures: Monthly numbers and percentages of SARS-CoV-2 infections and COVID-19-associated hospitalizations and deaths prevented were estimated among those who have been vaccinated in the US.

Results: COVID-19 vaccination was estimated to prevent approximately 27 million (95% uncertainty interval [UI], 22 million to 34 million) infections, 1.6 million (95% UI, 1.4 million to 1.8 million) hospitalizations, and 235 000 (95% UI, 175 000-305 000) deaths in the US from December 1, 2020, to September 30, 2021, among vaccinated adults 18 years or older. From September 1 to September 30, 2021, vaccination was estimated to prevent 52% (95% UI, 45%-62%) of expected infections, 56% (95% UI, 52%-62%) of expected hospitalizations, and 58% (95% UI, 53%-63%) of expected deaths in adults 18 years or older.

Conclusions and relevance: These findings indicate that the US COVID-19 vaccination program prevented a substantial burden of morbidity and mortality through direct protection of vaccinated individuals.

PubMed Disclaimer

Conflict of interest statement

Conflict of Interest Disclosures: None reported.

Figures

Figure.
Figure.. Median Estimated Monthly Number of Expected SARS-CoV-2 Infections and COVID-19–Associated Hospitalizations and Deaths Prevented by Vaccination per 100 000 Population by Age Group From December 1, 2020 to September 30, 2021, in the US
Error bars indicate 95% uncertainty intervals.
See this image and copyright information in PMC

Comment in

References

    1. World Health Organization. Coronavirus 2019 (COVID-19) Dashboard. Accessed May 24, 2022. https://covid19.who.int/
    1. Centers for Disease Control and Prevention. Trends in Number of COVID-19 Cases and Deaths in the US Reported to CDC, by State/Territory. Accessed May 24, 2022. https://covid.cdc.gov/covid-data-tracker/#trends
    1. Dooling K, Marin M, Wallace M, et al. . The Advisory Committee on Immunization Practices’ Updated Interim Recommendation for Allocation of COVID-19 Vaccine—United States, December 2020. MMWR Morb Mortal Wkly Rep. 2021;69(5152):1657-1660. doi:10.15585/mmwr.mm695152e2 - DOI - PMC - PubMed
    1. Centers for Disease Control and Prevention. COVID-19 Vaccinations in the United States. Accessed May 24, 2022. https://covid.cdc.gov/covid-data-tracker/#vaccination-demographics-trends
    1. Thompson MG, Burgess JL, Naleway AL, et al. . Prevention and attenuation of Covid-19 with the BNT162b2 and mRNA-1273 Vaccines. N Engl J Med. 2021;385(4):320-329. doi:10.1056/NEJMoa2107058 - DOI - PMC - PubMed

Publication types

Grants and funding