Safety of COVID-19 mRNA vaccination in patients with history of acquired hemophilia A: a case series

Coronavirus disease 2019 (COVID-19) following severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection called for a specific and massive vaccination campaign. Acquired hemophilia A (AHA) is a potential life-threatening coagulopathy. Hematological- targeted autoimmune conditions including immune thrombocytopenia, vaccine-induced thrombotic thrombocytopenia and AHA emerged during large-scale vaccination against SARS-CoV-2 and contributed to vaccination hesitation. The aim of the present study was to evaluate the putative recurrence of AHA after vaccination against SARS-CoV-2 with mRNA vaccines (BNT162b2 and mRNA- 1273) in patients with relatively recent history of AHA. Thirteen patients (8 women and 5 men, mean age = 63.1±16.6 years) with AHA in the previous two-to-five years were enrolled in the study. Platelet count, prothrombin time (PT), partial thromboplastin time (PTT), fibrinogen and Factor VIII levels were evaluated 48 hours prior to each vaccine dose and 10 days post-vaccination. Clinical self-assessment and remote video visits were performed in the presence of even minor hemorrhagic signs. No major bleeding events were detected at any time-point, including evaluation at 30 days after the 3rd vaccine dose. No significant hemorrhagic changes were observed, in particular no thrombocytopenia and/or significant alterations in PTT and Factor VIII emerged across subjects. Patients with a previous history of AHA of various etiology do not seem to have an increased recurrence risk after a COVID-19 vaccination course of 3 doses with either mRNA vaccine. This finding supports this specific safety aspect in the face of the possible continuation of the vaccination campaign based on the trend of the COVID-19 pandemic.