Nationwide COVID-19 vaccination coverage and COVID-19 incidence in South Korea, January 2022: a national official report

Abstract

Objective: To reduce the risk of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection, severe coronavirus disease 2019 (COVID-19) illness, and COVID-19 related death, all persons in South Korea should stay up to data with recommended COVID-19 vaccinations. This study investigated the rates and effectiveness of the COVID-19 vaccination in reducing the severity of disease of the entire Korean population. Methods: On January 2022, the official data released by the Korea Disease Control and Prevention Agency was analyzed. The types of COVID-19 vaccines (ChAdOx1-S [AstraZeneca], BNT162b2 [Pfizer-BioNTech], mRNA-1273 [Moderna], and Ad26.COV2.S [Janssen]), the cumulative cases, and the incidences of COVID-19 were estimated. The relative risk reduction of the severe COVID-19 cases was analyzed according to the histories of the COVID-19 vaccination. Results: On January 2022, the cumulative number of patients with COVID-19 cases was 642,207, with the incidence rate of 1,239 per 1,000,000 people. 82.22% [42,219,818/51,349,116] of Koreans have successfully been vaccinated two doses and 36.42% [13,709,545/51,349,116] were vaccinated a booster dose of the COVID-19. The relative risk reduction of severe COVID-19 was 27% (95% confidence interval [95% CI], 24 to 30) for the second dose of the COVID-19 vaccine and 79% (95% CI, 66 to 87) for the booster dose of the COVID-19 vaccine. In the ≥75 years old age group, the relative risk reduction of severe COVID-19 cases was 0.71 (95% CI, 0.69 to 0.73) for the second dose of COVID-19 vaccine and 0.99 (95% CI, 0.99 to 1.00) for the booster dose of COVID-19 vaccine. Conclusion: A maximum of high as 82.22% of Korean has been vaccinated two doses for COVID-19 until by January 2022. The COVID-19 vaccination was effective for reducing the severity of the COVID-19 in Korea. In addition, the preventive effect of COVID-19 vaccine for severe COVID-19 cases was high in old population.