Recommendations for intramuscular COVID-19 vaccination in patients with hemophilia

Background : Currently available COVID-19 vaccines were developed for intramuscular injection and efficacy may not be ensured when given subcutaneously. In Germany most traditional vaccines were recommended to inject subcutaneously in patients with hemophilia to avoid intramuscular bleeds. Aims : To develop practical guidance for COVID-19 vaccination in people with hemophilia. Methods : The Delphi methodology was used to develop consensus recommendations. An initial, structured list of recommendations was prepared by a steering committee and evaluated by 34 hemophilia experts. Consensus was defined as ≥75% agreement (score 7 or higher on a scale of 1 to 9);strong consensus was defined ≥95% agreement. After 3 rounds of refinement, a final list of statements was compiled. Results : Consensus was achieved that COVID-19 vaccines licensed only for intramuscular injection should also be administered through this route in people with hemophilia. Prophylactic factor replacement should be given before vaccination in patients with moderate or severe hemophilia, preferentially given on the day of vaccination, and with a maximum interval between prophylaxis and vaccination of 24 h (factor VIII and conventional factor IX concentrates) or 48 h (half-life extended factor IX). Strong consensus was also achieved that patients with mild hemophilia and residual activity >10% and patients on prophylaxis with emicizumab do not need factor replacement before vaccination. Swelling, erythema and hyperthermia after vaccination are not always signs of bleeding but should prompt consultation of the hemophilia care center. In case of injection site hematoma, patients should receive replacement therapy until symptoms disappear. Adjunctive therapies of injection site hematoma include rest, cooling and antiphlogistic/analgetic therapy as needed. Conclusions : Using the Delphi methodology, strong consensus was achieved on recommendations for intramuscular COVID-19 vaccination after replacement therapy for people with hemophilia depending on disease severity.