head felt as if it was a balloon and 2-3 sizes bigger than it is, no headache and no dizziness, just felt weird; felt weird; staggery; falling down; legs would just go out on me and then would be very very hard to get back up as if the muscles in my legs were not working; right side of face was partially numb feeling; very forgetful; confused state of mind; feet and hand would feel like pins and needles in them; Interchange of vaccine products; This is a spontaneous report received from contactable reporter(s) (Consumer or other non HCP). The reporter is the patient.  A 57-year-old female patient (not pregnant) received BNT162b2, BNT162b2 omi ba.4-5 (BNT162B2, BNT162B2 OMI BA.4-5), on 03Oct2022 at 15:15 as dose 5 (booster), single (Lot number: GH9703) at the age of 57 years, in right arm for covid-19 immunisation; influenza vaccine (INFLUENZA), on 03Oct2022 as dose number unknown, single (Batch/Lot number: unknown), in right arm for influenza immunisation. The patient's relevant medical history included: "Fibromyalgia" (unspecified if ongoing). The patient's concomitant medications were not reported. Past drug history included: Codeine, reaction(s): "drug allergy"; Codeine, reaction(s): "Known allergies: It only makes me itch". Vaccination history included: moderna (Dose 1, Single, Batch/Lot No: 012L20A, Location of injection: Arm Right, Vaccine Administration Time: 09:15 AM), administration date: 11Jan2021, for Covid-19 immunization; moderna (Dose 2, Single, Batch/Lot No: 011M20A, Location of injection: Arm Right, Vaccine Administration Time: 11:30 AM), administration date: 05Feb2021, for Covid-19 immunization; moderna (Dose 3, Single, Batch/Lot No: 056H21A, Location of injection: Arm Right, Vaccine Administration Time: 02:30 PM), administration date: 27Dec2021, for Covid-19 immunization; moderna (Dose 4, Single, Batch/Lot No: 056M21A, Location of injection: Arm Right, Vaccine Administration Time: 12:15 PM), administration date: 15May2022, for Covid-19 immunization. The following information was reported: INTERCHANGE OF VACCINE PRODUCTS (hospitalization, disability) with onset 03Oct2022 at 15:15, outcome "unknown"; CONFUSIONAL STATE (hospitalization, disability) with onset 31Jan2023 at 06:00, outcome "not recovered", described as "confused state of mind"; FALL (hospitalization, disability) with onset 31Jan2023 at 06:00, outcome "not recovered", described as "falling down"; PARAESTHESIA (hospitalization, disability) with onset 31Jan2023 at 06:00, outcome "not recovered", described as "feet and hand would feel like pins and needles in them"; FEELING ABNORMAL (hospitalization, disability) with onset 31Jan2023 at 06:00, outcome "not recovered", described as "felt weird"; HEAD DISCOMFORT (hospitalization, disability) with onset 31Jan2023 at 06:00, outcome "not recovered", described as "head felt as if it was a balloon and 2-3 sizes bigger than it is, no headache and no dizziness, just felt weird"; MUSCULAR WEAKNESS (hospitalization, disability) with onset 31Jan2023 at 06:00, outcome "not recovered", described as "legs would just go out on me and then would be very very hard to get back up as if the muscles in my legs were not working"; HYPOAESTHESIA (hospitalization, disability) with onset 31Jan2023 at 06:00, outcome "not recovered", described as "right side of face was partially numb feeling"; GAIT DISTURBANCE (hospitalization, disability) with onset 31Jan2023 at 06:00, outcome "not recovered", described as "staggery"; MEMORY IMPAIRMENT (hospitalization, disability) with onset 31Jan2023 at 06:00, outcome "not recovered", described as "very forgetful". The patient was hospitalized for interchange of vaccine products (hospitalization duration: 4 day(s)); for head discomfort, feeling abnormal, gait disturbance, fall, muscular weakness, hypoaesthesia, memory impairment, confusional state, paraesthesia (start date: 31Jan2023, hospitalization duration: 4 day(s)). The events "head felt as if it was a balloon and 2-3 sizes bigger than it is, no headache and no dizziness, just felt weird", "felt weird", "staggery", "falling down", "legs would just go out on me and then would be very very hard to get back up as if the muscles in my legs were not working", "right side of face was partially numb feeling", "very forgetful", "confused state of mind" and "feet and hand would feel like pins and needles in them" required emergency room visit. Therapeutic measures were not taken as a result of head discomfort, feeling abnormal, gait disturbance, fall, muscular weakness, hypoaesthesia, memory impairment, confusional state, paraesthesia. Clinical course: Facility type vaccine was reported as Pharmacy or Drug Store. The patient reported that her head felt as if it was a balloon and 2-3 sizes bigger than it was, no headache and no dizziness, just felt weird. She was very staggery and falling down. Her legs would just go out on her and then would be very very hard to get back up as if the muscles in her legs were not working. Her feet and hand would feel like pins and needles in them and her right right side of face was partially numb feeling. She was and still very forgetful, but the day at the hospital on 31Jan2023 she was not talking like she understood stuff. She was in a confused state of mind. She had to walk with a cane or a walker to get a round so she would not fall. She would not to be like this. Covid prior vaccination was reported as No and not covid tested post vaccination.