Journal of Preventive Medicine and Public Health

Review

Reassessing Early COVID-19 Strategies in East Asia: Insights From Japan and Korea: Duk-Hee Lee, Hideki Kakeya; J Prev Med Public Health. 2026;59(4):343-351. Published online June 24, 2026; DOI: https://doi.org/10.3961/jpmph.26.274

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Abstract Summary PDF Supplementary Material: East Asian countries had remarkably low coronavirus disease 2019 (COVID-19) mortality in 2020, a pattern widely cited as evidence of effective public health interventions. However, Japan and Korea—often classified as having followed similar early intervention strategies—adopted substantially different approaches. These differences are largely obscured by commonly used stringency indices and policy score analyses. While neither country implemented a lockdown, Korea pursued an aggressive, government-mandated strategy based on extensive testing, isolation, quarantine, and compulsory data collection. In contrast, Japan relied on a voluntary model with limited mass testing, a policy that drew strong criticism during the early phase of the pandemic. Because asymptomatic COVID-19 infection was highly prevalent, these divergent testing policies were particularly important in shaping patterns of community transmission. Using excess mortality as a comprehensive outcome metric, Japan’s outcomes were as favorable as Korea’s through the pre-Omicron period, despite Japan’s limited testing. In 2020, excess mortality was negligible in both countries (−1.7% in Japan vs. +0.3 to +2.1% in Korea). In 2021, excess mortality increased modestly (+2.2% vs. +4.0 to +5.6%). However, in 2022, despite approximately 80% vaccination coverage in both countries, excess mortality reached +7.6% in Japan and about +20% in Korea—three times the Japanese level despite Korea’s much higher booster rate. These patterns of excess mortality in 2 countries with contrasting testing strategies challenge the view that East Asia’s early success stemmed primarily from stringent virus suppression measures. They highlight the need to consider alternative explanations, including the possibility that pre-existing immunity differed substantially across geographical regions.; Summary

Korean summary
- 2020년 동아시아는 서구 국가들에 비해 훨씬 낮은 코로나19 사망률을 기록하며 성공적인 팬데믹 대응의 모범 사례로 평가받았으나 한국과 일본은 상당히 다른 방역 정책을 가진 국가이다. - 본 연구는 다양한 강제적 전파억제 조치와 대규모 진단검사를 시행한 한국과, 제한적인 진단검사와 자율적 방역 정책을 채택한 일본의 팬데믹 성과를 비교하였다. - 2020년 양국 모두 초과사망은 미미하였으나, 2022년에는 높은 백신 접종률에도 불구하고 초과사망이 급증했으며 특히 한국은 일본보다 약 3배 높은 초과사망을 보였다. 이러한 결과는 2020년 동아시아의 낮은 코로나19 사망률이 역정책보다 지역 간 교차면역 수준의 차이에 의해 더 잘 설명될 수 있음을 시사한다.

Key Message
- In 2020, East Asia recorded far lower COVID-19 mortality than Western countries and was regarded as a model of successful pandemic control. However, Korea and Japan adopted markedly different strategies. - This study compared pandemic outcomes between Korea with mandatory transmission- suppression measures and mass testing, and Japan with limited testing and voluntary mitigation. - Excess mortality was minimal in both countries in 2020 but rose sharply in 2022 despite high vaccination coverage, with Korea’s excess mortality three times that of Japan. These findings suggest that cross-immunity may better explain East Asia’s low pandemic impact than public health measures.

Original Articles

Excess Deaths in Korea During the COVID-19 Pandemic: 2020-2022: So-Jin Im, Ji-Yeon Shin, Duk-Hee Lee; J Prev Med Public Health. 2024;57(5):480-489. Published online August 20, 2024; DOI: https://doi.org/10.3961/jpmph.24.254

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Abstract Summary PDF Supplementary Material

Objectives
Excess deaths, an indicator that compares total mortality rates before and during a pandemic, offer a comprehensive view of the pandemic’s impact. However, discrepancies may arise from variations in estimating expected deaths. This study aims to compare excess deaths in Korea during the coronavirus disease 2019 pandemic using 3 methods and to analyze patterns using the most appropriate method.
Methods
Expected deaths from 2020 to 2022 were estimated using mortality data from 2015-2019 as reference years. This estimation employed 3 approaches: (1) simple average, (2) age-adjusted average, and (3) age-adjusted linear regression. Excess deaths by age, gender, and cause of death were also presented.
Results
The number of excess deaths varied depending on the estimation method used, reaching its highest point with the simple average and its lowest with the age-adjusted average. Age-adjusted linear regression, which accounts for both the aging population and declining mortality rates, was considered most appropriate. Using this model, excess deaths were estimated at 0.3% for 2020, 4.0% for 2021, and 20.7% for 2022. Excess deaths surged among individuals in their 20s throughout the pandemic, largely attributed to a rise in self-harm and suicide. Additionally, the results indicated sharp increases in deaths associated with “endocrine, nutritional, and metabolic diseases” and “symptoms, signs, and abnormal clinical and laboratory findings, not elsewhere classified.”
Conclusions
Substantial variations in excess deaths were evident based on estimation method, with a notable increase in 2022. The heightened excess deaths among young adults and specific causes underscore key considerations for future pandemic responses.

Summary

Korean summary
초과 사망은 팬데믹 영향을 종합적으로 평가하는 핵심 지표로 잘 알려져 있으나, 추정 방법에 따라 결과가 다양한 것으로 보고되고 있다. 코로나19 팬데믹동안 흔하게 사용된 3가지 방법 – 단순 평균, 연령보정 평균, 연령 보정 선형 회귀식-을 이용하여 초과사망을 추정하였을 때, 추정 방법에 따라서 초과사망에 큰 차이가 있었다. 3가지 방법 중 인구 고령화와 사망률 감소 추이를 고려한 연령 보정 선형 회귀식이 가장 적절한 것으로 판단되었으며, 이 방법을 이용한 한국의 초과 사망은 2020년 0.3%, 2021년 4.0%, 2022년 20.7%로 추정되었다. 또한 팬데믹 전 기간 동안 20대 초과 사망이 급증했는데 이는 주로 자해와 자살의 증가로 인한 것이었으며, '내분비, 영양 및 대사 질환' 및 ' 달리 분류되지 않은 증상, 징후와 임상 및 검사의 이상소견”으로 인한 초과사망도 급증하였다.

Key Message
● Excess deaths, a comprehensive indicator of the pandemic’s impact, varied by estimation method.
● Using an age-adjusted linear regression approach, which considers an aging population and declining mortality rates, excess deaths in Korea during the COVID-19 pandemic were estimated at 0.3% for 2020, 4.0% for 2021, and 20.7% for 2022.
● Excess deaths surged among individuals in their 20s throughout the pandemic, mainly due to increased self-harm and suicide, alongside a sharp rise in deaths related to ‘endocrine, nutritional, and metabolic diseases’, and ‘symptoms, signs, and abnormal clinical and laboratory findings, not elsewhere classified’.

Citations

Citations to this article as recorded by

Imputing missing data with statistical-learning estimates: impacts on mortality risks attributable to area- and source-specific PM2.5.
Youngkwon Kim, Cinoo Kang, Seung-Muk Yi, JongBae Heo, Hwajin Kim, Woojoo Lee, Ho Kim, Philip K. Hopke, Young Su Lee, Hye-Jung Shin, Jungmin Park, Myungsoo Yoo, Kwonho Jeon, Jieun Park
Atmospheric Pollution Research.2026; 17(3): 102785. CrossRef
Integrated Clinical and Social Impacts of the COVID-19 Pandemic in Korea: A Combined Systematic and Narrative Review
Yumi Jang, Jaehun Jung, Kyong Ran Peck
Journal of Korean Medical Science.2026;[Epub] CrossRef
Excess mortality from gastric cancer in Korea during the COVID-19 pandemic, 2020–2023
Gyeongil Kim, Ji-Yeon Shin, Yu-Mi Lee, Duk-Hee Lee
Epidemiology and Health.2026; 48: e2026021. CrossRef
Cause of death statistics in 2022 in the Republic of Korea
Jung-Hyun Oh, Juhee Seo, Hyun Jung Park
Ewha Medical Journal.2025; 48(3): e46. CrossRef
Excess mortality and healthcare costs during the COVID-19 pandemic among patients with ten major chronic diseases in South korea: a nationwide analysis
Jihun Song, Hye Jun Kim, Seogsong Jeong, Sun Jae Park, Hyun-Young Shin, Eun-kyeong Jeong, Jaehun Jung, Geehyuk Kim, Sang Min Park
BMC Infectious Diseases.2025;[Epub] CrossRef

Excess Deaths During the COVID-19 Pandemic in Southern Iran: Estimating the Absolute Count and Relative Risk Using Ecological Data: Mohammadreza Zakeri, Alireza Mirahmadizadeh, Habibollah Azarbakhsh, Seyed Sina Dehghani, Maryam Janfada, Mohammad Javad Moradian, Leila Moftakhar, Mehdi Sharafi, Alireza Heiran; J Prev Med Public Health. 2024;57(2):120-127. Published online February 7, 2024; DOI: https://doi.org/10.3961/jpmph.23.198

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308 Download
5 Web of Science
3 Crossref

Abstract Summary PDF Supplementary Material

Objectives
The coronavirus disease 2019 (COVID-19) pandemic led to increased mortality rates. To assess this impact, this ecological study aimed to estimate the excess death counts in southern Iran.
Methods
The study obtained weekly death counts by linking the National Death Registry and Medical Care Monitoring Center repositories. The P-score was initially estimated using a simple method that involved calculating the difference between the observed and expected death counts. The interrupted time series analysis was then used to calculate the mean relative risk (RR) of death during the first year of the pandemic.
Results
Our study found that there were 5571 excess deaths from all causes (P-score=33.29%) during the first year of the COVID-19 pandemic, with 48.03% of these deaths directly related to COVID-19. The pandemic was found to increase the risk of death from all causes (RR, 1.26; 95% confidence interval [CI], 1.19 to 1.33), as well as in specific age groups such as those aged 35-49 (RR, 1.21; 95% CI, 1.12 to 1.32), 50-64 (RR, 1.38; 95% CI, 1.28 to 1.49), and ≥65 (RR, 1.29; 95% CI, 1.12 to 1.32) years old. Furthermore, there was an increased risk of death from cardiovascular diseases (RR, 1.17; 95% CI, 1.11 to 1.22).
Conclusions
There was a 26% increase in the death count in southern Iran during the COVID-19 pandemic. More than half of these excess deaths were not directly related to COVID-19, but rather other causes, with cardiovascular diseases being a major contributor.

Summary

Key Message
During the first year of the COVID-19 pandemic in southern Iran, there was a notable increase in excess deaths, representing a 33.29% rise compared to expected figures. Approximately half of these excess deaths were directly attributed to COVID-19. Moreover, the pandemic heightened the risk of death across all causes by 26%, with specific age groups, notably those aged 50-64, experiencing heightened vulnerability. Notably, cardiovascular diseases emerged as a significant contributor to excess mortality during this period, while decreases were observed in deaths related to chronic respiratory diseases and cancers.

Citations

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BMC Cardiovascular Disorders.2026;[Epub] CrossRef
Utilization of Acid Suppressants After Withdrawal of Ranitidine in Korea: An Interrupted Time Series Analysis
Jeong Pil Choi, Sangwan Kim, Jung Su Park, Mi-Sook Kim, Nam-Kyong Choi, Cheol Min Shin, Joongyub Lee
Journal of Preventive Medicine and Public Health.2025; 58(1): 21. CrossRef
Lived experiences of COVID-19 survivors admitted to the respiratory intensive care unit (RICU): phenomenological study in Southern Iran
Esmaeil Barkhori Mehni, Foozieh Rafati, Mohsen Abbasi, Shideh Rafati, Sudabeh Ahmadidarrehsima
BMC Psychology.2025;[Epub] CrossRef

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