Correspondence on COVID-19 Vaccination and Acquired Haemophila A.

Dear Editor, we would like to correspond and share ideas on the publication “Haemostatic Disarray Following COVID-19 Vaccine - a Case of Acquired Haemophila A (AHA). ” A case of AHA was described by O'Shea et al one week after receiving the Pfizer-BioNTech SARS-CoV-2 vaccination. “O'Shea et al examined the immunopathogenesis of AHA caused by the COVID-19 vaccination. We agree that the patient had AHA after receiving COVID-19 vaccine. It is important to remember, however, that not all clinical problems in vaccine recipients are caused by immunization. Other probable causes of AHA should be considered in this circumstance. The underlying illnesses in this patient were prostate cancer and non-insulin dependent diabetes. There has been a link between these two disorders and AHA.[2,3] The present patient was given rituximab and steroid. Six weeks following diagnosis, his Factor VIII level was normal and his inhibitor screen was negative. Rituximab is also an adjuvant therapy that has been shown to be helpful in the treatment of prostate cancer. When it is applied, it might have anti-tumor effect on the prostate cancer. In addition to the abnormal immune induced by COVID-19 vaccine, it's possible that the AHA in this situation is caused by the cancer.