hematologic anemia; I was not feeling very well; sick; This is a spontaneous report received from a contactable reporter(s) (Consumer or other non HCP), Program ID: Unknown. The reporter is the patient.  A male patient received BNT162b2 (BNT162B2), as dose 3 (booster), single (Lot number: FC3184, Expiration Date: 31Oct2021), in left arm for covid-19 immunisation. The patient's relevant medical history was not reported. Concomitant medication(s) included: METFORMIN (ongoing); LOSARTAN + HIDROCLOROTIAZIDA (ongoing). Vaccination history included: BNT162b2 (Dose 1, Single, Lot number: EN6200), administration date: 19Apr2021, for COVID-19 immunisation; Bnt162b2 (Dose 2, Single, Batch/lot number: unknown.), for COVID-19 immunization. The following information was reported: HAEMOLYTIC ANAEMIA (medically significant), outcome "not recovered", described as "hematologic anemia"; MALAISE (non-serious), outcome "not recovered", described as "I was not feeling very well"; ILLNESS (non-serious), outcome "not recovered", described as "sick". The event "hematologic anemia" required physician office visit. The patient underwent the following laboratory tests and procedures: Blood test: (14Oct2021) Unknown result. Therapeutic measures were taken as a result of haemolytic anaemia, malaise, illness. Clinical course: It was reported that his primary doctor said to contact them to let know what was going on. Start date of Pfizer Covid-19 Vaccine was the first vaccine was 19Feb2021 and then he could not read the second one was and his last one. Product details (LOT and Expiration date) of Pfizer Covid-19 Vaccine was the LOT was EN6200, that was the first one. The Expiration date was 10/31 of 2021 and he have a LOT on that one, that was his last shot (Pfizer Covid-19 Vaccine Booster), the LOT was FC3184. The Expiration date of Pfizer Covid-19 Vaccine having the LOT FC3184 was 31Oct2021. First dose of Pfizer Covid-19 Vaccine has no expiration date on it. Anatomical site of Vaccination was left upper arm. Expiry Date and UPC number of Covid-19 Vaccine was Unknown. Expiry Date and UPC number of Prednisone was Unknown. Reason for no lot number of Prednisone was Consumer stated, he cannot find the LOT. There was not a LOT, nothing, he does not know, does not say. Call was transferred from Regulatory Authority Support Call Center (ID: 159558). Transferring agent stated, they have a patient on the other line and he has mentioned that he was diagnosed since March with hematologic anemia and his Hematologist stated that he had this side effect after getting the Covid-19 Vaccine (clarified as Pfizer Covid-19 Vaccine). Transferring agent stated, he mentioned that he was already being treated. So, he was currently taking the medication Prednisone. Consumer confirmed that, Yes, the Doctor started him at 100mg for one month, then the next month was 80 and then the next month was 60, the next month was 40 and then now was 20, now the patient was at 20 and it was determined that it (Prednisone) was not helping at all. Consumer was informed about the role of Pfizer Drug Safety. He stated, his Primary Doctor yesterday told that some of his other patients also have the same symptoms he was having with the Pfizer Shot (Pfizer Covid-19 Vaccine). When probed for the information about the patients, in response Consumer stated, he do not, that was not, that was the HIPPA Law. Other medical Conditions was he take medication Metformin forever and Losartan HCTZ forever.  Follow-up attempts are completed. No further information is expected.