ArticleScientific reports2023
Evaluating the COVID-19 vaccination program in Japan, 2021 using the counterfactual reproduction number.
Article in Scientific reports, 2023. The graph could read no effect estimate from its abstract, so it casts no vote on the map. An erratum has been issued. Cited by 17 papers, 1 of them a synthesis that pooled it.
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The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.
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Trials whose registry record cites this paper, or whose number appears in the abstract. A trial that started after this paper was published is citing it as background, not reporting it.
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Who cites it
17 citing papers in PubMed, 1 synthesis or guideline pooled it.
- Assessing the Impact of COVID-19 Vaccination Programs on the Reduction of COVID-19 Cases: A Systematic Literature Review.Annals of global health · 2024Pooled it
- The Imperative of Data Transparency for Pursuing Scientific Truth about COVID-19 Vaccination and Excess Deaths.JMA journal · 2026Article
- Impact of the COVID-19 pandemic on thoracic surgery volume in Japan: an analysis of the National Clinical Database.Surgery today · 2026Article
- The public health impact of extending the catch-up nonavalent human papillomavirus vaccination program to 2028 in Japan: a model-based study.BMC public health · 2025Article
- Estimating Population Immunity and Impact of COVID-19 Vaccination in Washington State and Oregon.Open forum infectious diseases · 2025Article
- Large-scale screening of SARS-CoV-2 variants in Tokyo, Japan: A 3-year and 9-month longitudinal survey.Global health & medicine · 2025Article
- Quantifying the direct and indirect components of COVID-19 vaccine effectiveness during the Delta variant era.Epidemiology and infection · 2025Article
- Examining the role of social environment on COVID-19 infections and vaccine uptake among migrants in Japan: Findings from nationwide surveys in 2021 and 2023.Journal of migration and health · 2025Article
- Review
- Epidemiological impact of revoking mask-wearing recommendation on COVID-19 transmission in Tokyo, Japan.Infectious Disease Modelling · 2024Article
- Article
- Clinical Course and Factors Correlated with Severe Morbidity and Mortality in Patients with Coronavirus Disease 2019 Undergoing Maintenance Dialysis in Kanagawa, Japan.Internal medicine (Tokyo, Japan) · 2024Observational
- Impact of COVID-19 Vaccination in Thailand: Averted Deaths and Severe Infections Across Age Groups.Tropical medicine and infectious disease · 2024Article
- Public Health and Economic Impact of Periodic COVID-19 Vaccination with BNT162b2 for Old Adults and High-Risk Patients in an Illustrative Prefecture of Japan: A Budget Impact Analysis.Infectious diseases and therapy · 2024Article
- Science-based exit from stringent countermeasures against COVID-19: Mortality prediction using immune landscape between 2021 and 2022 in Japan.Vaccine: X · 2024Article
- Increase in antibody titer and change over time associated with severe acute respiratory syndrome coronavirus 2 infection after mRNA vaccination: Consideration of the significance of additional vaccination.Clinical case reports · 2024Article
- The Scabbard of Excalibur: An Allegory on the Role of an Efficient and Effective Healthcare System under Universal Health Coverage during the Pandemic Response.Healthcare (Basel, Switzerland) · 2024Article
Corrections and comments
- Erratum issued
- Erratum issued
Authors and funding
6 authors.
Funding
No grant is acknowledged in the PubMed record.
Abstract
Japan implemented its nationwide vaccination program against COVID-19 in 2021, immunizing more than one million people (approximately 1%) a day. However, the direct and indirect impacts of the program at the population level have yet to be fully evaluated. To assess the vaccine effectiveness during the Delta variant (B.1.617.2) epidemic in 2021, we used a renewal process model. A transmission model was fitted to the confirmed cases from 17 February to 30 November 2021. In the absence of vaccination, the cumulative numbers of infections and deaths during the study period were estimated to be 63.3 million (95% confidence interval [CI] 63.2-63.6) and 364,000 (95% CI 363-366), respectively; the actual numbers of infections and deaths were 4.7 million and 10,000, respectively. Were the vaccination implemented 14 days earlier, there could have been 54% and 48% fewer cases and deaths, respectively, than the actual numbers. We demonstrated the very high effectiveness of COVID-19 vaccination in Japan during 2021, which reduced mortality by more than 97% compared with the counterfactual scenario. The timing of expanding vaccination and vaccine recipients could be key to mitigating the disease burden of COVID-19. Rapid and proper decision making based on firm epidemiological input is vital.
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Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.