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Impact of vaccination on the COVID-19 pandemic in U.S. states

Chen, Xiao, Huang, Hanwei, Ju, Jiandong, Sun, Ruoyan and Zhang, Jialiang (2022) Impact of vaccination on the COVID-19 pandemic in U.S. states. Scientific Reports, 12 (1). ISSN 2045-2322

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Identification Number: 10.1038/s41598-022-05498-z


Governments worldwide are implementing mass vaccination programs in an effort to end the novel coronavirus (COVID-19) pandemic. Here, we evaluated the effectiveness of the COVID-19 vaccination program in its early stage and predicted the path to herd immunity in the U.S. By early March 2021, we estimated that vaccination reduced the total number of new cases by 4.4 million (from 33.0 to 28.6 million), prevented approximately 0.12 million hospitalizations (from 0.89 to 0.78 million), and decreased the population infection rate by 1.34 percentage points (from 10.10 to 8.76%). We built a Susceptible-Infected-Recovered (SIR) model with vaccination to predict herd immunity, following the trends from the early-stage vaccination program. Herd immunity could be achieved earlier with a faster vaccination pace, lower vaccine hesitancy, and higher vaccine effectiveness. The Delta variant has substantially postponed the predicted herd immunity date, through a combination of reduced vaccine effectiveness, lowered recovery rate, and increased infection and death rates. These findings improve our understanding of the COVID-19 vaccination and can inform future public health policies.

Item Type: Article
Official URL:
Additional Information: © 2022 The Authors
Divisions: Centre for Economic Performance
Subjects: H Social Sciences > HV Social pathology. Social and public welfare. Criminology
R Medicine > RA Public aspects of medicine > RA0421 Public health. Hygiene. Preventive Medicine
Date Deposited: 10 Feb 2022 15:15
Last Modified: 17 Apr 2024 19:21

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