Hemoglobin was 9.4 on 31Mar2021 and 7.7 on 27Apr2021; destruction of red blood cell; This is a spontaneous report received from a contactable reporter(s) (Consumer or other non-HCP). The reporter is the patient.  A 63-year-old male patient received bnt162b2 (BNT162B2), administered in arm left, administration date 27Mar2021 (Lot number: Er8733) at the age of 63 years as dose 2, single and administered in arm left, administration date 06Mar2021 (Lot number: En6205) as dose 1, single for covid-19 immunization. Relevant medical history included: "Multiple Myeloma - in remission" (ongoing). Concomitant medication(s) included: REVLIMID, start date: 01Apr2021, stop date: 27Apr2021 for Multiple Myeloma - in remission. Past drug history included: Velcade, start date: Nov2020, stop date: 28Feb2021, for Multiple Myeloma, reaction(s): "Hemoglobin moved in the range of 10.5 to 11.5.", notes: My Hemoglobin moved in the range of 10.5 to 11.5.; Revlimid, start date: Nov2020, stop date: 28Feb2021, for Multiple Myeloma, reaction(s): "Hemoglobin moved in the range of 10.5 to 11.5.", notes: My Hemoglobin moved in the range of 10.5 to 11.5. The patient did not receive any other vaccines within 4 weeks prior to the COVID vaccine. The patient did not receive any other medications the patient received within 2 weeks of vaccination. The patient has no known allergies. The patient was neither diagnosed with COVID-19 Prior to vaccination, nor been tested for COVID-19 Since the vaccination. The following information was reported: HAEMOLYSIS (medically significant) with onset 2021, outcome "unknown", described as "destruction of red blood cell"; HAEMOGLOBIN DECREASED (medically significant) with onset 31Mar2021, outcome "not recovered", described as "Hemoglobin was 9.4 on 31Mar2021 and 7.7 on 27Apr2021". The event "hemoglobin was 9.4 on 31mar2021 and 7.7 on 27apr2021" was evaluated at the physician office visit. Clinical course as follows: During a period from Nov2020 to Feb2021, the patient was on Valcade and Revlemid (as part of MM maintenance program). During that period, Hemoglobin moved in the range of 10.5 to 11.5. On 28Feb2021, the patient stopped both medications (per doctor's recommendation) for the March Pfizer vaccine. The patient received first shot of covid vaccine on 06Mar2021. The hemoglobin decreased to 9.4 on 31Mar2021. On 01Apr2021 I resumed Revlemid (10mg/day). The patient received Second dose on 27Mar2021. On 27Apr2021, Hemoglobin was 7.7.  Therefore, immediately stopped Revlemid. Since then, Hemoglobin has been moving in 7.5 to 9.0 range. Over the last 9 months, the patient had 6 different hematologists/oncologists work on identifying the root cause. Dozens of tests were conducted, including 2 bone marrow biopsies and two extensive next gene sequencing tests. The tests indicate destruction of red blood cells. The patient underwent the following laboratory tests and procedures: biopsy bone marrow: (2021) destruction of red blood cells.; gene sequencing: (2021) destruction of red blood cells; haemoglobin: (28Feb2021) 10.5; (31Mar2021) 9.4; (27Apr2021) 7.7; (2021) 10.5 to 11.5. Therapeutic measures were not taken as a result of haemoglobin decreased. The patient had dose 3 (Booster), lot no: Fc3180 on left arm on 07Sep2021.  No follow-up attempts are possible. No further information is expected.