SynthesisBlood reviews2021
The impact of ABO blood group on COVID-19 infection risk and mortality: A systematic review and meta-analysis.
Synthesis in Blood reviews, 2021. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 92 papers, 4 of them syntheses that pooled it.
What it found
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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.
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.
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Who cites it
92 citing papers in PubMed, 4 syntheses or guidelines pooled it, 184 citations in OpenAlex.
- ABO and Rhesus blood groups and multiple health outcomes: an umbrella review of systematic reviews with meta-analyses of observational studies.BMC medicine · 2024Pooled it
- ABO blood group and risk of COVID-19 infection and complications: A systematic review and meta-analysis.Transfusion · 2022Pooled it
- Systematic review and meta-analysis of the effect of ABO blood group on the risk of SARS-CoV-2 infection.PloS one · 2022Pooled it
- Systematic review and meta-analysis of the susceptibility of ABO blood group to COVID-19 infection.Transfusion and apheresis science : official journal of the World Apheresis Association : official journal of the European Society for Haemapheresis · 2021Pooled it
- Impact of ABO Blood System on Immunogenicity and Vaccine Efficacy of COVID-19 Booster Vaccination-A Population-Based Study of 3066 Individuals.Influenza and other respiratory viruses · 2026Article
- SARS-CoV-2 Infection-Induced Alterations in ADAR Editing Patterns Differ Between Patients Who Developed Critical Compared to Non-Critical COVID-19.International journal of molecular sciences · 2026Article
- ABO Blood Types and Mortality in Patients Undergoing Hemodialysis.Kidney international reports · 2026Article
- Prevalence of ABO Blood Groups and Their Relationship with Vascular Access Thrombosis and Mortality in Hemodialysis Patients.Medicina (Kaunas, Lithuania) · 2026Article
- Blood Group Antigen Combinations and COVID-19: Complexity, Associations and Possible Clinical Relevance.Life (Basel, Switzerland) · 2026Article
- Paleopathology Meets Public Health: Deep-Time Syndemics and the Ecology of Emerging Infections.Pathogens (Basel, Switzerland) · 2026Review
- ABO Discrepancy in Multiple Myeloma Initially Suspected as a Complication of COVID-19 Vaccination.Cureus · 2026Article
- A retrospective study on the association between ABO blood group and the severity and prognosis of hospitalized Chinese patients with COVID-19.BMC infectious diseases · 2025Article
- Do certain blood groups increase COVID-19 severity and mortality?Global epidemiology · 2025Article
- Association of HLA-B gene polymorphism and blood groups with COVID-19 susceptibility and severity.Scientific reports · 2025Article
- Determining population-specific risk factors for COVID-19 susceptibility and severity to inform future individual-level integrated risk scoring.BMC infectious diseases · 2025Article
- Genetic association of preeclampsia to von Willebrand factor and its size-regulator ADAMTS13.Research square · 2025Article
- Article
- ABO blood group and COVID-19 severity: Associations with endothelial and adipocyte activation in critically ill patients.PloS one · 2025Article
- COVID-19 and blood group-related antigens: can natural anti-carbohydrate antibodies provide innate protection from symptomatic SARS-CoV-2 infection?Frontiers in medicine · 2025Article
- Development of a nomogram for high antibody titre of COVID-19 convalescent plasma.Epidemiology and infection · 2024Article
32 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
8 authors at 3 institutions in 1 country.
Funding
No grant is acknowledged in the PubMed record.
Abstract
The 2019 coronavirus disease (COVID-19) has become a global pandemic. Several studies report that ABO blood group polymorphism may be related to COVID-19 susceptibility and clinical outcomes; however, the results are controversial. We conducted a systematic review and meta-analysis to investigate whether ABO blood groups are associated with increased COVID-19 morbidity and mortality. A total of 715 articles were retrieved from seven databases. Ten articles were selected for meta-analysis after removal of duplicates and two levels of screenings. Overall, individuals with blood group A [odds ratio (OR) = 1.33, 95% confidence interval (CI) 1.14 to 1.56] and B (OR = 1.06, 95% CI 1.00 to 1.13) had a substantially higher risk of COVID-19, whereas this was not the case for blood group AB (OR = 1.07, 95% CI 0.88 to 1.30). Individuals with blood group O was not prone to develop the disease (OR = 0.71, 95% CI 0.60 to 0.84). Moreover, the risk of COVID-19 was significantly associated with the Rh-positive blood group (OR = 1.22, 95% CI 0.99 to 1.50). A meta-analysis of 5 studies suggested that blood group A was associated with a significantly increased risk of COVID-19 mortality (OR = 1.25, 95% CI 1.02 to 1.52). Mild publication bias was found in the included studies. This systematic review and meta-analysis indicated that blood groups A and B may be risk factors for COVID-19, whereas the blood group O appears to be protective. Blood group A may be related to unfavourable outcomes. Further rigorous and high-quality research evidence is needed to confirm this association.
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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.