key: cord-1050211-v4i9e36e authors: Sriwijitalai, Won; Wiwanitkit, Viroj title: Correspondence on “Immune thrombocytopenia in 2 healthy young women after the Pfizer‐BioNTech BNT16B2b2 messenger RNA coronavirus disease 2019 vaccination” date: 2022-01-15 journal: J Am Coll Emerg Physicians Open DOI: 10.1002/emp2.12625 sha: 3dbdb6ee5d8eb1c1a3df9d22025263d4fddaa199 doc_id: 1050211 cord_uid: v4i9e36e nan The following 3 possible scenarios for thrombocytopenia after vaccination exist 1 : abnormal immune response to the vaccine, 2 a preexisting thrombohemostasis problem or platelet disorder, and 3 an unrelated subsequent medical problem (eg, dengue). In consideration of the first mechanism, a COVID-19 vaccine stimulates the immune system and the abnormal antibodies, including antiplatelet antibodies, might occur in some vaccine recipients. 2 The abnormal immune response is usually mentioned as a possible mechanism. 2 Immune thrombocytopenia in 2 healthy young women after the Pfizer-BioNTech BNT16B2b2 messenger RNA coronavirus disease 2019 vaccination Thrombotic thrombocytopenia after COVID-19 vaccination: in search of the underlying mechanism. Vaccines (Basel) Epidemiology and clinical manifestations of immune thrombocytopenia Exacerbation of immune thrombocytopenia following COVID-19 vaccination Dengue after COVID-19 vaccination: possible and might be missed