Prevnar 13 Associated Immune Thrombocytopenic Purpura; This is a literature report for the following literature source(s):  A 77-year-old male patient received pneumococcal 13-val conj vac (dipht CRM197 protein) (PREVNAR 13), in Apr2023 as dose number unknown, single (Batch/Lot number: unknown) for immunisation. The patient's relevant medical history included: "increased bruising at insulin injection sites" (unspecified if ongoing), notes: for 1 week; "End-Stage Renal Disease" (unspecified if ongoing); "hypertension" (ongoing); "diabetes mellitus 2" (ongoing); "kidney allograft" (unspecified if ongoing), notes: 22 months ago; "petechial rash" (unspecified if ongoing). The patient's concomitant medications were not reported. Past drug history included: Insulin; Tacrolimus for Immunosuppression; Mycophenolate mofetil for Immunosuppression, reaction(s): "BK viremia"; Prednisone for Immunosuppression; Allopurinol; Asa; Statin; Bactrim; Carvedilol; Insulin glargine; Insulin aspart. The following information was reported: IMMUNE THROMBOCYTOPENIA (hospitalization, medically significant), outcome "recovered", described as "Prevnar 13 Associated Immune Thrombocytopenic Purpura". Clinical courses is as follows: A 77 year old male presented with chief complaint of increased bruising at insulin injection sites for one week. There was no history of fever, abdominal pain, diarrhea, bleeding episodes, neurological deficits, new medications or insect bites. He had ESRD secondary to hypertension and DM2.He received a living unrelated kidney allograft 22mo ago. He was on tacrolimus, MMF, prednisone, MMF later discontinued indefinitely due to BK viremia. Family history was non-contributory. Medications included allopurinol, ASA, statin, bactrim, carvedilol, insulin glargine and aspart, prednisone and tacrolimus. He received Prevnar13 1 month ago. Exam showed normal vital signs and petechial rash in the areas of insulin injections. Lab testing resulted in Hb 11.7 & WBC 7.7(baseline) and platelet 3000 (baseline 140).BUN 31 and Cr1.50 (baseline). PT,PTT,LDH and haptoglobin were normal. No schistocytes seen. Infectious workup was negative and ADAMTS-13 activity resulted at 102%. The isolated thrombocytopenia was diagnosed as ITP and was attributed to the Prevnar 13 vaccine. He was started on pulse dose steroids and IVIG. He received 6 units platelets with counts increasing to 94000, later discharged on a prednisone taper.Weekly blood counts showed improvement to his baseline of 140,000 in 3 weeks.  No follow-up attempts are possible; information about lot/batch number cannot be obtained. No further information is expected.; Sender's Comments: Based on the temporal relationship, the association between the event immune thrombocytopenia with PREVNAR 13 can not be completely excluded.  The impact of this report on the benefit/risk profile of the Pfizer product is evaluated as part of Pfizer procedures for safety evaluation, including the review and analysis of aggregate data for adverse events. Any safety concern identified as part of this review, as well as any appropriate action in response, will be promptly notified to regulatory authorities, Ethics Committees, and Investigators, as appropriate.