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. 2023 Jun;14(3):164-172.
doi: 10.24171/j.phrp.2023.0096. Epub 2023 Jun 22.

Estimating the number of severe COVID-19 cases and COVID-19-related deaths averted by a nationwide vaccination campaign in Republic of Korea

Ji Hae Hwang  1 , Ju Hee Lee  1 , Eun Jung Jang  1 , Ryu Kyung Kim  1 , Kil Hun Lee  1 , Seon Kyeong Park  1 , Sang Eun Lee  1 , Chungman Chae  1 , Sangwon Lee  1 , Young Joon Park  1
Affiliations

Estimating the number of severe COVID-19 cases and COVID-19-related deaths averted by a nationwide vaccination campaign in Republic of Korea

Ji Hae Hwang et al. Osong Public Health Res Perspect. 2023 Jun.

Abstract

Background: The Korea Disease Control and Prevention Agency promotes vaccination by regularly providing information on its benefits for reducing the severity of coronavirus disease 2019 (COVID-19). This study aimed to analyze the number of averted severe COVID-19 cases and COVID-19-related deaths by age group and quantify the impact of Republic of Korea's nationwide vaccination campaign.

Methods: We analyzed an integrated database from the beginning of the vaccination campaign on February 26, 2021 to October 15, 2022. We estimated the cumulative number of severe cases and COVID-19-related deaths over time by comparing observed and estimated cases among unvaccinated and vaccinated groups using statistical modeling. We compared daily age-adjusted rates of severe cases and deaths in the unvaccinated group to those in the vaccinated group and calculated the susceptible population and proportion of vaccinated people by age.

Results: There were 23,793 severe cases and 25,441 deaths related to COVID-19. We estimated that 119,579 (95% confidence interval [CI], 118,901-120,257) severe COVID-19 cases and 137,636 (95% CI, 136,909-138,363) COVID-19-related deaths would have occurred if vaccination had not been performed. Therefore, 95,786 (95% CI, 94,659-96,913) severe cases and 112,195 (95% CI, 110,870-113,520) deaths were prevented as a result of the vaccination campaign.

Conclusion: We found that, if the nationwide COVID-19 vaccination campaign had not been implemented, the number of severe cases and deaths would have been at least 4 times higher. These findings suggest that Republic of Korea's nationwide vaccination campaign reduced the number of severe cases and COVID-19 deaths.

Keywords: COVID-19; Patient acuity; Republic of Korea; SARS-CoV-2; Vaccination campaign.

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Conflict of interest statement

Conflicts of Interest

The authors have no conflicts of interest to declare.

Figures

Figure 1.
Figure 1.
Flow chart of the study population.
Figure 2.
Figure 2.
Weekly trends in the age-adjusted incidence of COVID-19 and vaccination coverage.
Figure 3.
Figure 3.
Weekly trends in the age-adjusted incidence of severe COVID-19 cases and COVID-19-related deaths by vaccination status. (A) COVID-19-related severe cases. (B) COVID-19-related deaths.
See this image and copyright information in PMC

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