OC 70.2 - Safety of Intramuscular COVID-19 Vaccination in Patients With Hemophilia

Wednesday, July 13, 2022

10:30 AM – 10:45 AM

Location: ExCel Center, S11A

Presentation Format: In-Person

Presenting Author(s)

Andreas Tiede, MD PhD

Professor of Hemostasis and Thrombosis
Department of Hematology, Hemostasis, Oncology and Stem Cell Transplantation, Hannover Medical School, Hannover, Germany
Hannover, Niedersachsen, Germany

Co-Author(s)

HL

Hendrik Leise

Research associate
Hannover Medical School
Hannover, Niedersachsen, Germany
SH

Silvia Horneff

Physician
Bonn University
Bonn, Nordrhein-Westfalen, Germany
JO

Johannes Oldenburg

Director of the Institute of Experimental Haematology and Transfusion Medicine
University Clinic Bonn, Institute of Experimental Haematology and Transfusion Medicine, Bonn, Germany
Bonn, Berlin, Germany
Susan Halimeh, MD

Professor
Gerinnungszentrum Rhein Ruhr, Duisburg, Germany
Duisburg, Nordrhein-Westfalen, Germany
CH

Christine Heller

Physician
Frankfurt University
Frankfurt, Hessen, Germany
Königs Christoph, Dr. Dr.

Physician
Goethe University Frankfurt, University Hospital, Department of Pediatrics and Adolescent Medicine, Clinical and Molecular Haemostasis, Frankfurt am Main, Germany
Frankfurt, Hessen, Germany
HK

Holstein Katharina

physician
University Hospital Hamburg Eppendorf
Hamburg, Hamburg, Germany
CP

Christian Pfrepper, MD

Physician
Division of Hemostaseology, University Hospital Leipzig, Germany
Leipzig, Sachsen, Germany

Background: Guidelines recommend that patients with hemophilia should preferably receive vaccination subcutaneously rather than intramuscularly. COVID-19 vaccines, however, are only licensed for intramuscular application.

Aims: To assess the safety of intramuscular COVID-19 vaccination in patients with hemophilia.

Methods: This observational multicenter study consisted of two parts. Part A enrolled consecutive patients with hemophilia A (HA) and B (HB) of all ages and severities and assessed injection site bleeding and other complications within 30 days of vaccination. Part B enrolled patients providing informed consent for more detailed data collection including medication and prophylaxis around the time of vaccination.

Results: Four hundred and sixty-one patients were enrolled by six institutions into part A (HA 389 [84%], HB 72 [16%]; severe 291 [63%], moderate 61 [13%], mild 109 [24%]). The primary endpoint injection site bleeding occurred in 7 patients (1.5%, 95% confidence interval 0.6-3.1%), including 5 with severe HA, 1 moderate HA, and 1 mild HB. Analysis of 214 patients in part B revealed that 97% of patients with severe hemophilia, who were not on emicizumab, had received factor prophylaxis before vaccination, either as part of their regular regime (60%) or additionally (40%). Only one patient on emicizumab received additional factor. The bleeding patients with severe HA had received factor within 2-17h before vaccination and had no clinical characteristics that could have explained the bleeding. Factor was also given to 26% and 60% of mild and moderate patients not on regular prophylaxis, respectively. The two bleeding patients in this group had not received concentrate before vaccination. Other side effects of vaccination were comparable with studies in the general population.

Conclusion(s): This is the first study reporting on the safety of intramuscular COVID-19 vaccination in hemophilia. The rate of injection site bleeding was below 3%, comparable with the general population.