Consensus Recommendations for Intramuscular COVID-19 Vaccination in Patients with Hemophilia

Currently available coronavirus disease 2019 (COVID-19) vaccines are approved for intramuscular injection and efficacy may not be ensured when given subcutaneously. For years, subcutaneous vaccination was recommended in patients with hemophilia to avoid intramuscular bleeds. Therefore, recommendations for the application of COVID-19 vaccines are needed.

The Delphi methodology was used to develop consensus recommendations. An initial list of recommendations was prepared by a steering committee and evaluated by 39 hemophilia experts. Consensus was defined as ≥75% agreement and strong consensus as ≥95% agreement, and agreement as a score ≥7 on a scale of 1 to 9. After four rounds, a final list of statements was compiled.

Consensus was achieved that COVID-19 vaccines licensed only for intramuscular injection should be administered intramuscularly in hemophilia patients. Prophylactic factor replacement, given on the day of vaccination with a maximum interval between prophylaxis and vaccination of 24 hours (factor VIII and conventional factor IX concentrates) or 48 hours (half-life extended factor IX), should be provided in patients with moderate or severe hemophilia. Strong consensus was achieved that patients with mild hemophilia and residual factor activity greater than 10% with mild bleeding phenotype or patients on emicizumab usually do not need factor replacement before vaccination. Swelling, erythema, and hyperthermia after vaccination are not always signs of bleeding but should prompt consultation of a hemophilia care center. In case of injection-site hematoma, patients should receive replacement therapy until symptoms disappear.

Consensus was achieved on recommendations for intramuscular COVID-19 vaccination after replacement therapy for hemophilia patients depending on disease severity.