immune thrombocytopenia; This is a Literature report , 2021, volume 10 (1), DOI: 10.1186/s40164-021-00235-0, entitled "COVID-19 vaccination associated severe immune thrombocytopenia".   Case: A 53-year-old male Herein, we report three cases of severe ITP that occurred following COVID-19 vaccination and their outcome. Case #1 A 53-year-old man with past medical history of Crohn's disease well-controlled with Ustekinumab, and no prior history of thrombocytopenia or exposure to heparin was seen in [redacted] with symptoms of intermittent episodes of high-grade fever with chills, diffuse myalgia and petechial rash over chest, abdomen and extremities that had started 2 days prior. He did not have symptoms of coryza, cough, headache, abdominal pain, rectal bleeding, dysuria, diarrhea or altered sensorium. He had received the second of the two doses of Pfizer- BioNTech COVID-19 vaccine 8 days prior to the onset of symptoms. In the ED, he had a temperature of 39 centigrade. He had petechiae in the oropharynx, anterior trunk and bilateral upper and lower extremities. Rest of the physical exam was unremarkable. A complete blood count (CBC) showed a platelet count of 2 x 109/ L. Rest of the blood counts and red cell indices were normal. Peripheral blood film did not show platelet clumping or schistocytes. Current list of medications didn't reveal any culprit medications and he had normal platelet count (254 x109/ L) 5 weeks prior. Urinalysis, Blood cultures and X-ray chest did not show any evidence of infectious etiology and he remained afebrile throughout hospital course. Viral respiratory panel including influenza A and B, RSV and COVID-19 was negative. Hepatitis C and HIV serology was non-reactive. Coagulation profile was normal. Computed tomography (CT) of the head, chest, abdomen and pelvis did not show any evidence of thrombosis. Spleen measured 14.2 cm. Complement levels and autoimmune panel including anti double stranded DNA antibody and anti CCP antibody was normal. Bone marrow biopsy showed normocellular bone marrow with mildly increased megakaryopoiesis, preserved trilineage hematopoiesis without atypia or increased blasts. Flow cytometry didn't show any abnormal B cells without an increase in CD 34 positive blasts. He received intravenous immunoglobulin (IVIG) 1 g/kg/day for 2 consecutive days and oral dexamethasone 40 mg/day for 4 consecutive days. With this regimen, the platelet count normalized in about 4 days after initiation of therapy and the response was durable. (Fig. 1). Our report describes three cases of severe ITP that occurred following COVID-19 vaccination and also provides insights into the treatment and outcomes for ITP secondary to COVID-19 vaccination. All three patients responded well to treatment with corticosteroids +- IVIG. If the treatments (IVIG and/or steroids) utilized in our cases were not effective, and the platelet count remained very low, it would then be reasonable to escalate therapy to include a thrombopoietic agent, and potentially vinca alkaloids, depending upon response.; Sender's Comments: based on the available information the causal relationship suspect vaccine and the serious event immune thrombocytopaenic purpura cannot be completely ruled out  ,Linked Report(s) : US-PFIZER INC-202100941146 same article/suspect/event, different patient.