ABO blood group influence COVID-19 infection: a meta-analysis

J Infect Dev Ctries. 2021 Dec 31;15(12):1801-1807. doi: 10.3855/jidc.13815.


Introduction: Previous studies have linked the relationship between ABO blood group and COVID-19 infection. However, existing evidence is preliminary and controversial. This meta-analysis sought to identify studies that describe COVID-19 and ABO blood group.

Methodology: A literature search was conducted from PubMed, Web of Science, MedRxiv, BioRxiv and Google Scholar databases. Members of cases and controls were extracted from collected studies. Pooled Odds ratio (OR) and 95% confidence interval (95%CI) were calculated and interpreted from extracted data. Publication bias and sensitivity analysis were also applied to confirm our discovery.

Results: Total 13,600 patients and 3,445,047 controls were included in the study. Compared to other ABO blood group, blood group O was associated with a lower risk of COVID-19 infection (OR = 0.76, 95%CI 0.66-0.84), while blood group A and AB was associated with a higher risk (OR = 1.25, 95%CI 1.10-1.41; OR = 1.13, 95%CI 1.04-1.23, respectively). In the subgroup analysis, the relationship between blood group A, O and COVID-19 infection remained stable among Chinese, European and Eastern Mediterranean populations. In American population, blood groups B was linked with increased risk of COVID-19 infection (OR = 1.21, 95%CI 1.09-1.35).

Conclusions: Our data suggested that individuals with blood types A and AB are more susceptible to COVID-19, while people with blood type O are less susceptible to infection. More research is needed to clarify the precise role of the ABO blood group in COVID-19 infection to address the global question.

Keywords: ABO blood group; COVID-19; coronavirus disease 2019; meta-analysis.

Publication types

  • Meta-Analysis
  • Review

MeSH terms

  • ABO Blood-Group System*
  • COVID-19 / blood*
  • COVID-19 / epidemiology
  • Disease Susceptibility / blood*
  • Global Health
  • Humans
  • Pandemics
  • Risk Assessment
  • SARS-CoV-2


  • ABO Blood-Group System