ArticleVaccine2021
Evaluation of post-introduction COVID-19 vaccine effectiveness: Summary of interim guidance of the World Health Organization.
Article in Vaccine, 2021. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 91 papers, 2 of them syntheses that pooled it.
What it found
Each row is one number read from the abstract, on the scale the paper reported it, with its interval. Left of the dashed line favours the treatment, right favours the comparator. Under each row is the sentence it came from. New to these charts? A ten-minute tutorial.
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.
The trial behind it
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.
Neither the registry nor the abstract names a trial number. If this is a trial report, that itself is worth knowing.
Who cites it
91 citing papers in PubMed, 2 syntheses or guidelines pooled it, 154 citations in OpenAlex.
- Risk of myocarditis and pericarditis in mRNA COVID-19-vaccinated and unvaccinated populations: a systematic review and meta-analysis.BMJ open · 2023Pooled it
- Real-world effectiveness of COVID-19 vaccines: a literature review and meta-analysis.International journal of infectious diseases : IJID : official publication of the International Society for Infectious Diseases · 2022Pooled it
- Programmatic Effectiveness of a Pediatric Typhoid Conjugate Vaccine Campaign in Navi Mumbai, India.Clinical infectious diseases : an official publication of the Infectious Diseases Society of America · 2023Trial
- Immunogenicity of a fractional or full third dose of AZD1222 vaccine or BNT162b2 messenger RNA vaccine after two doses of CoronaVac vaccines against the Delta and Omicron variants.International journal of infectious diseases : IJID : official publication of the International Society for Infectious Diseases · 2023Trial
- Comparative effectiveness of BNT162b2 and ChAdOx1 nCoV-19 vaccines against COVID-19.BMC medicine · 2023Trial
- Durability of protection and immunogenicity of AZD1222 (ChAdOx1 nCoV-19) COVID-19 vaccine over 6 months.The Journal of clinical investigation · 2022Trial
- The effectiveness of COVID-19 vaccines and the added benefit of booster doses in Hessen, Germany, during the COVID-19 pandemic: Results from a vaccinated-only study.Human vaccines & immunotherapeutics · 2026Article
- The effect of Covid-19 vaccines on semen parameters of patients undergoing infertility investigations: a self-controlled before-and-after study.Scientific reports · 2026Article
- Proposed study design for estimating COVID-19 vaccine effectiveness in post-pandemic Taiwan.Journal of the Chinese Medical Association : JCMA · 2026Article
- Article
- Lack of harmonisation in immunological data: challenges in synthesising data during the COVID-19 pandemic.EBioMedicine · 2026Review
- COVID-19 vaccination and mortality among coronary care patients with severe acute respiratory infection in Bangladesh: a prospective study (2021-2024).The Lancet regional health. Southeast Asia · 2026Article
- Global disparities in the introduction, scale-up, and effectiveness evaluation of COVID-19 vaccines.Nature communications · 2025Article
- Adults in Ghana generate higher and more durable neutralising antibody titres following primary course COVID-19 vaccination than matched UK adults: The HERITAGE Study.BMC medicine · 2025Article
- Evaluating the Test-Negative Design for COVID-19 Vaccine Effectiveness Using Randomized Trial Data: A Secondary Cross-Protocol Analysis of 5 Randomized Clinical Trials.JAMA network open · 2025Article
- Perceptions about COVID-19 vaccine among healthcare workers in Rwanda: A mixed-methods study.Journal of public health in Africa · 2025Article
- Article
- Relationship between HLA genetic variations, COVID-19 vaccine antibody response, and risk of breakthrough outcomes.Nature communications · 2024Article
- The impact of underreported infections on vaccine effectiveness estimates derived from retrospective cohort studies.International journal of epidemiology · 2024Article
- Vaccines reduced hospital length of stay and fraction of inspired oxygen of COVID-19 patients: A retrospective cohort study.Preventive medicine reports · 2024Article
31 more citing papers are in PubMed but not listed here.
Corrections and comments
PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.
Authors and funding
27 authors at 16 institutions in 9 countries.
Funding
Abstract
Phase 3 randomized-controlled trials have provided promising results of COVID-19 vaccine efficacy, ranging from 50 to 95% against symptomatic disease as the primary endpoints, resulting in emergency use authorization/listing for several vaccines. However, given the short duration of follow-up during the clinical trials, strict eligibility criteria, emerging variants of concern, and the changing epidemiology of the pandemic, many questions still remain unanswered regarding vaccine performance. Post-introduction vaccine effectiveness evaluations can help us to understand the vaccine's effect on reducing infection and disease when used in real-world conditions. They can also address important questions that were either not studied or were incompletely studied in the trials and that will inform evolving vaccine policy, including assessment of the duration of effectiveness; effectiveness in key subpopulations, such as the very old or immunocompromised; against severe disease and death due to COVID-19; against emerging SARS-CoV-2 variants of concern; and with different vaccination schedules, such as number of doses and varying dosing intervals. WHO convened an expert panel to develop interim best practice guidance for COVID-19 vaccine effectiveness evaluations. We present a summary of the interim guidance, including discussion of different study designs, priority outcomes to evaluate, potential biases, existing surveillance platforms that can be used, and recommendations for reporting results.
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What OpenQuestion holds
Registered trials
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.