Hypoxia; anemia; tachycardia; decreased red blood cell count; decreased hematocrit; low iron; very low ferritin level; periodic skin irritations with itching and non-specific patchy dermatoses; periodic skin irritations with itching and non-specific patchy dermatoses; periodic skin irritations with itching and non-specific patchy dermatoses; This is a spontaneous report received from contactable reporter(s) (Other HCP). The reporter is the patient.  A 75-year-old female patient (not pregnant) received BNT162b2 (BNT162B2), on 27Sep2021 as dose 3 (booster), single (Lot number: 301308A), in left arm for covid-19 immunisation. The patient's relevant medical history was not reported. Concomitant medication(s) included: PREMARIN; POSTURE D [CALCIUM PHOSPHATE;COLECALCIFEROL;ERGOCALCIFEROL]; D3. Past drug history included: Sulfa medication, reaction(s): "Drug Allergy". Vaccination history included: BNT162b2 (Dose Number: 2, Batch/Lot No: EN6203, Location of injection: Arm Left), administration date: 01Mar2021, for COVID-19 immunization; BNT162b2 (Dose Number: 1, Batch/Lot No: EL9262, Location of injection: Arm Left), administration date: 08Feb2021, for COVID-19 immunization. The following information was reported: HYPOXIA (medically significant), outcome "recovered with sequelae"; ANAEMIA (non-serious), outcome "recovered with sequelae", described as "anemia"; TACHYCARDIA (non-serious), outcome "recovered with sequelae"; RED BLOOD CELL COUNT DECREASED (non-serious), outcome "recovered with sequelae", described as "decreased red blood cell count"; HAEMATOCRIT DECREASED (non-serious), outcome "recovered with sequelae", described as "decreased hematocrit"; BLOOD IRON DECREASED (non-serious), outcome "recovered with sequelae", described as "low iron"; SERUM FERRITIN DECREASED (non-serious), outcome "recovered with sequelae", described as "very low ferritin level"; SKIN IRRITATION (non-serious), PRURITUS (non-serious), DERMATOSIS (non-serious), outcome "recovered with sequelae" and all described as "periodic skin irritations with itching and non-specific patchy dermatoses". The events "hypoxia", "anemia", "tachycardia", "decreased red blood cell count", "decreased hematocrit", "low iron", "very low ferritin level" and "periodic skin irritations with itching and non-specific patchy dermatoses" required physician office visit. The patient underwent the following laboratory tests and procedures: Blood test: (unspecified date) Unknown Result; SARS-CoV-2 antibody test: (22Dec2021) Negative, notes: Nasal Swab. Therapeutic measures were taken as a result of hypoxia, anaemia, tachycardia, red blood cell count decreased, haematocrit decreased, blood iron decreased, serum ferritin decreased, skin irritation, pruritus, dermatosis.  Clinical course: The patient underwent the following laboratory tests and procedures once 2.5 months after the second shot, and again 5.5 months after the third shot.  The patient received adverse event treatment slow Fe for 45 days on the first episode. The patient did not receive any other vaccines within four weeks prior to the vaccination. Prior to the vaccination, the patient was not diagnosed with COVID-19. Patient received multivitamin as concomitant drug.  No follow-up attempts are possible. No further information is expected.; Sender's Comments: As there is limited information in the case provided, the causal association between the event Hypoxia and the suspect drug cannot be excluded. The case will be reassessed once new information is available.