For the neutrophils, white blood cells which were way down to point of critical, they were all of a sudden tanking; For the neutrophils, white blood cells which were way down to point of critical, they were all of a sudden tanking; ITP (Idiopathic thrombocytopenic purpura); Low platelet count/platelets were 47 th/uLv platelets were 47 th/uL, which th stands for thousands, in uL, which is the content of blood /41 th/uL/56 th/uL; This is a spontaneous report received from a contactable reporter(s) (Consumer or other non HCP) from medical information team.  A 75 year-old female patient received bnt162b2 (BNT162B2), administered in arm left, administration date 06Oct2021 (Lot number: 30155BA) at the age of 74 years as dose 3 (booster), single for covid-19 immunisation. Relevant medical history included: "ITP", start date: 2017 (unspecified if ongoing), notes: Caller says this was diagnosed four years ago, before she got the vaccines.; "Bleeding", stop date: 2017, notes: Stating that the wife had not experienced bleeding since 2017. There were no concomitant medications. Vaccination history included: Bnt162b2 (Dose 1, LOT: EP6955, Anatomical location: Left arm, NDC/EXP were not provided for the first dose), administration date: 15Mar2021, when the patient was 74 years old, for COVID-19 immunization; Bnt162b2 (Dose 2, LOT: EP7533, Anatomical location: Left arm, NDC/EXP were not provided for the second dose), administration date: 05Apr2021, when the patient was 74 years old, for COVID-19 immunization. The following information was reported: IMMUNE THROMBOCYTOPENIA (medically significant) with onset Feb2022, outcome "unknown", described as "ITP (Idiopathic thrombocytopenic purpura)"; PLATELET COUNT DECREASED (medically significant) with onset 25Jan2022, outcome "unknown", described as "Low platelet count/platelets were 47 th/uLv platelets were 47 th/uL, which th stands for thousands, in uL, which is the content of blood /41 th/uL/56 th/uL"; WHITE BLOOD CELL COUNT DECREASED (medically significant), NEUTROPHIL COUNT DECREASED (medically significant), outcome "unknown" and all described as "For the neutrophils, white blood cells which were way down to point of critical, they were all of a sudden tanking". The events "itp (idiopathic thrombocytopenic purpura)", "low platelet count/platelets were 47 th/ulv platelets were 47 th/ul, which th stands for thousands, in ul, which is the content of blood /41 th/ul/56 th/ul", "for the neutrophils, white blood cells which were way down to point of critical, they were all of a sudden tanking" and "for the neutrophils, white blood cells which were way down to point of critical, they were all of a sudden tanking" were evaluated at the physician office visit. The patient underwent the following laboratory tests and procedures: blood test: (Feb2022) low platelet count, notes: She had low platelet count and was Diagnosed with ITP (Idiopathic thrombocytopenic purpura); (Feb2022) diagnosed with itp, notes: She had low platelet count and was Diagnosed with ITP (Idiopathic thrombocytopenic purpura); investigation: (unspecified date) they seemed really, really good; neutrophil count: (unspecified date) which were way down to point of critical, notes: they were all of a sudden tanking, but he doesn't know if these are related to vaccine or not. No further details provided about other lab results; platelet count: (unspecified date) unknown results, notes: he doesn't know when the decline for her platelets; (25Jan2022) 47, notes: th/uL More information available (Y/N): No; (02Feb2022) 41, notes: th/uL More information available (Y/N): No; (09Feb2022) 56, notes: th/uL More information available (Y/N): No; white blood cell count: (unspecified date) which were way down to point of critical, notes: they were all of a sudden tanking, but he doesn't know if these are related to vaccine or not. No further details provided about other lab results. Therapeutic measures were not taken as a result of immune thrombocytopenia. Clinical course: it was reported that no treatment for the idiopathic thrombocytopenia, not under current diagnosis, but she is going to undergo a bone marrow biopsy on Monday 14Feb.Consumer says he is calling on behalf of his wife about the Pfizer COVID-19 vaccine. He says he and his wife both had all three shots of COVID vaccine, and it appears not without certainty after a follow up visit to her hematologist that after her booster dose in Oct2021, when his wife visited the hematologist her platelet level and total blood chemistry had been altered by vaccine, but maybe not. He says he has read online where the National Institute of Health and Medicine said 12% of patients suffered a severe reaction of idiopathic thrombocytopenia. He says that his wife is diagnosed with that right now, and she may have had an adverse reaction to Pfizer COVID-19 vaccine. He says it appears like everything with her labs were going well until her last booster in Oct, which it is 4 months later and her blood platelets and white blood cells and everything are crazy. He says according to the data from PubMed and withheld, 12% of patients have had severe ITP, which whether or not that is accurate or not, is on their website. Caller provides information from the article which call handler was unable to clarify as caller continued speaking. Caller provides the following from the article: Cases of apparent secondary immune thrombocytopenia reaction after vaccine have been reported in the public and reached public attention. Caller provides web address for this article as: withheld, and says that it was published 09Mar. AE: idiopathic thrombocytopenia: Caller asks, is there any documentation that Pfizer is aware of that idiopathic thrombocytopenia is happening with the vaccine, since it says here it is happening with both Pfizer and Moderna. He says he has been reading stuff that he had heard nowhere else, on the internet, so he doesn't know if his wife's hematologist would be aware. He says it seems to be coincidental, but he doesn't know when the decline for her platelets and blood cells started.   No follow-up attempts are possible. No further information is expected.