The pathophysiology of AHA in the context of COVID-19 vaccination remains to be elucidated; however, it is thought that the immune response triggered by the vaccine might play a role in the development of autoantibodies against FVIII.[21] The median of 14 days (1 week to 3 weeks in 13 patients, Table 1) from vaccination to diagnosis supports the immune reaction as the underlying mechanism. The gene discussed is F8; the disease is autoimmune hemolytic anemia.