Acquired hemophilia A (AHA) due to anti-SARS-CoV-2 vaccination: A systematic review

Vaccination against SARS-CoV2 has been the largest vaccination campaign over the past two decades. The aim of this study is to qualitatively assess the reported cases of acquired hemophilia A (AHA) that developed after COVID-19 vaccination to further elaborate on incidence, presentation, treatment, and outcomes.We queried Medline (PubMed), Google Scholar, and Embase databases to find reported cases of AHA after COVID-19 vaccines. We found 14 studies (19 cases) for this descriptive analysis. Most patients were elderly (mean age 73 years) and males (n = 12) with multiple comorbidities. All cases developed after mRNA vaccines - BNT162b2 Pfizer-BioNTech (n = 13) and mRNA-1273 Moderna (n = 6). All except one patient were treated, with the most common therapy being a combination of steroids, immunosuppression, and rFVIII (n = 13). Two patients died due to acute respiratory distress, and gall bladder rupture with persistent bleeding, respectively. While evaluating a patient with bleeding diathesis after COVID-19 vaccination, AHA should be kept in the differential diagnosis. Given the low incidence, we believe that the benefit of vaccination still outweighs the risk of disease acquisition.