dizziness; low blood pressure; 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 71-year-old female patient received BNT162b2 (COMIRNATY), on 14Apr2022 at 10:45 as dose 4 (booster), single (Lot number: FK9894) at the age of 71 years, in left arm for covid-19 immunisation. The patient's relevant medical history included: "little light headed" (unspecified if ongoing), notes: Before she would get a little light headed and once every 4 months; "Pain" (unspecified if ongoing), notes: In the past, she has reacted to a drug supposed to be for pain. There were no concomitant medications. Vaccination history included: BNT162b2 (DOSE 1, SINGLE, Lot EN6206 expiration is unknown.Injected in left upper arm.), administration date: 03Mar2021, when the patient was 69-year-old, for COVID-19 Immunization; BNT162b2 (DOSE 2, SINGLE, Lot EN6204, expiration is unknown.Injected in left upper arm.), administration date: 24Mar2021, when the patient was 69-year-old, for COVID-19 Immunization; BNT162b2 (DOSE 3, SINGLE, Lot FE3590, expiration is unknown.Injected in left upper arm.), administration date: 21Oct2021, when the patient was 70-year-old, for COVID-19 Immunization. The following information was reported: DIZZINESS (non-serious) with onset 14Apr2022 at 13:30, outcome "not recovered"; HYPOTENSION (non-serious) with onset 14Apr2022 at 13:30, outcome "not recovered", described as "low blood pressure". Relevant laboratory tests and procedures are available in the appropriate section.  Additional Information: Patient was asking whether Pfizer Covid-19 booster, batch FK9894, cause dizziness that won't subside within 3 hours of receiving the drug. It was stated that in a clinical study of participants 18 through 55 years of age, adverse reactions following administration of a first booster dose were pain at the injection site (83.0%), fatigue (63.7%), headache (48.4%), muscle pain (39.1%), chills (29.1%), joint pain (25.3%), lymphadenopathy (5.2%), nausea (0.7%), decreased appetite (0.3%), rash (0.3%), and pain in extremity (0.3%). No information specific to dizziness. A review of the Prescribing Information for <Pfizer Product Name> did not find information regarding dizziness. As the Prescribing Information does not include all adverse reactions that had been reported or that may occur, patient was asked to consult with the doctor/healthcare provider about what she had experienced/are experiencing. Because the doctor/healthcare provider was most familiar with her medical condition, clinical history, how her treatment had been conducted and any relevant information to her specific case, her doctor/healthcare provider was in the best position to advise about the appropriate action to take.Patient stated that she has been experiencing dizziness since then and has been persisting and wanted to know when the dizziness will go away. Patient was Informed that dizziness had not been associated with the vaccine and that the list does not include all possible side effects and was informed that systemic reactions usually lasted 1 day for patients 18 years and older. Patient was advised to consult with her doctor. Patient wanted to know if the serum she received on 14Apr2022 can damage her autoimmune system. Patient later clarified that she was referring to Pfizer COVID-19 Vaccine. Patient stated that she received the Pfizer COVID-19 Vaccine for her 1st and 2nd dose and 1st booster dose. Informed patient that there was no information on the Pfizer COVID-19 Vaccine causing damage to the immune system. Mechanism of action was that the vaccine elicits an immune response to the S antigen, which protects against COVID-19. Informed patient that the vaccine she received for her 2nd booster dose is the same as the ones she received before. Report was not related to a study or programme. No further Investigations. Pfizer COVID vaccine booster manufacturer was unspecified. NDC number of Pfizer COVID vaccine booster was Unknown. Expiry Date of Pfizer COVID vaccine booster was Unknown. Patient stated within 3 hours after receiving it, she was dizzy and so she had to go to bed because it was not safe to walk around and has been dizzy. 4th dose was injected in left upper arm. Patient said since that date, she had low blood pressure and it had not been bothering her. When it did, she would just eat more food. After the injection, she was getting dizzy almost constantly and went to a dietician and said she needed more protein 3 times a day and drink a lot of water. She has been following that method but is still dizzy. She said whenever she goes into her doctor, it has been low but not really diagnosed. When she let her know about the dizziness, she has not gotten back to her yet. Attempted to confirm when the low blood pressure first started when she started to notice it at the doctor's office and caller stated it was 14Apr2022. Attempted to clarify again and unable to clarify when she went to doctor and first noticed it as caller still stated 14Apr2022, which was the date she got the booster. Before she would get a little lightheaded and once every 4 months or so from the low blood pressure. Now it is constant. She wanted to know when will this dizziness will go away. She had been eating protein at least 60 a day for probably the last 3 weeks or so. She listened to a talk, and she talked about low blood pressure and eating protein. Vaccination Facility Type was Pharmacy. No additional Vaccines Administered on Same Date of the Pfizer Suspect. AE(s) does not require a visit to Emergency Room and Physician Office. No other vaccinations were received within four weeks prior to the first administration date of the suspect vaccine(s). No AE(s) following prior vaccinations. In the past, she has reacted to a drug that she cannot remember the name and is supposed to be for pain. It was 15 years ago. It keeps her awake 24 hours. She does not have a name, lot or expiration. Family Medical History Relevant to AE(s) was none. Relevant Tests was None.  No follow-up attempts possible. No further information expected.