low iron; His hemoglobin was 5.9, which can result in major problems, and he spent a day and a half in the hospital getting blood transfusions; The initial case was missing the following minimum criteria: Caused/prolonged hospitalization . Upon receipt of follow-up information on (18Oct2022), this case now contains all required information to be considered valid.  This is a spontaneous report received from contactable reporter(s) (Consumer or other non HCP) from medical information team. The reporter is the patient.  A 66-year-old male patient received BNT162b2, BNT162b2 omi ba.4-5 (BNT162B2, BNT162B2 OMI BA.4-5), on 13Sep2022 as dose 5 (booster), single (Lot number: GH9702) at the age of 65 years for covid-19 immunisation. The patient's relevant medical history and concomitant medications were not reported. Vaccination history included: BNT162b2 (dose:1, of LOT: EL9261, NDC/EXP: not provided), administration date: 31Jan2021, when the patient was 64-year-old, for COVID-19 immunization, reaction(s): "low iron"; BNT162b2 (dose:2, LOT: EN6200, NDC/EXP: not provided,), administration date: 21Feb2021, when the patient was 64-year-old, for COVID-19 immunization, reaction(s): "low iron"; BNT162b2 (dose:3, LOT: FF8841, no NDC/EXP provided), administration date: 20Sep2021, for COVID-19 immunization, reaction(s): "low iron"; BNT162b2 (DOSE:4, LOT: FM0698, no NDC/EXP provided), administration date: 05Apr2022, for COVID-19 immunization, reaction(s): "low iron". The following information was reported: BLOOD IRON DECREASED (hospitalization, medically significant), outcome "unknown", described as "low iron"; HAEMOGLOBIN DECREASED (hospitalization, medically significant), outcome "unknown", described as "His hemoglobin was 5.9, which can result in major problems, and he spent a day and a half in the hospital getting blood transfusions". The patient was hospitalized for blood iron decreased, haemoglobin decreased (start date: 11Oct2022). The events "low iron" and "his hemoglobin was 5.9, which can result in major problems, and he spent a day and a half in the hospital getting blood transfusions" required emergency room visit. The patient underwent the following laboratory tests and procedures: Blood test: (unspecified date) Unknown result; Haemoglobin: (unspecified date) 10.5; (unspecified date) low, notes: iron levels were very low/iron levels were depleted; (10Oct2022) 5.9. Therapeutic measures were taken as a result of blood iron decreased, haemoglobin decreased.  Clinical information: Patient stated that, for the average male hemoglobin is supposed to be 13.5, and his dropped to 10.5 initially, so they were not overly worried, it was not good but it was not bad. He said, this started about 30-40 days after his first vaccine in Mar2021, and when they first started noticing they didn't correlate it with the vaccine. He doesn't know his iron level for that time. For treatment, they first started him on iron supplements over the counter, 36.5mg once a day. Now they have him on three times a day, after they had him on twice a day. He has been having low iron for a year, and his iron was so bad recently that he had to have infusions. He doesn't know the lab values for his low iron. For the last three months they have given him infusions along with the over-the-counter iron supplements. This last week hemoglobin dropped to half that and he was put in the hospital because it was so low. When hemoglobin drops to 5, it is a deadly situation and can result in death, which 5.9 was his hemoglobin level. The patient felt really sick that day, and he called his doctor who wanted him to have blood tests done, that was on Monday. After she got the results, she called him at eight o'clock at night and told him to go to emergency room and have a blood transfusion. His hemoglobin was 5.9, which can result in major problems, and he spent a day and a half in the hospital getting blood transfusions. He clarified that this was a week ago Monday, on 10Oct. He went to the hospital in the evening to the emergency room, where he was for four hours before they admitted him to the hospital on 11Oct at 01:00 AM, that was when they decided he had to have an infusion. This coming Thursday will be patient's 12th infusion of iron, plus taking OTC iron supplements three times a day. Patient reported that, his Iron was depleted, and this happened after Pfizer vaccination, so he wanted to follow up and let people know.  No follow-up attempts are needed. No further information is expected.