terrible slowing down, could barely walk/getting around is more difficult/gate issues/barely walk across the parking lot or up the stairs; unfortunately due to his gate issues, slip and hit his head; This is a spontaneous report received from contactable reporter(s) (Other HCP). The reporter is the patient.  A 69-year-old male patient received BNT162b2 (BNT162B2), on 22Feb2021 as dose 2, single (Lot number: FK9729, Expiration Date: 31May2022) at the age of 69 years for covid-19 immunisation. The patient had no relevant medical history. There were no concomitant medications. Vaccination history included: BNT162b2 (DOSE1, Single; Pfizer COVID-19 Vaccine, Strength: 0.3mL, Lot number: EN6201, Expiration Date: 30Jun2021), administration date: 29Jan2021, when the patient was 69-year-old, for COVID-19 Immunization. The following information was reported: GAIT DISTURBANCE (medically significant) with onset 22Feb2021, outcome "not recovered", described as "terrible slowing down, could barely walk/getting around is more difficult/gate issues/barely walk across the parking lot or up the stairs"; HEAD INJURY (medically significant) with onset 22Feb2021, outcome "recovered", described as "unfortunately due to his gate issues, slip and hit his head". The events "terrible slowing down, could barely walk/getting around is more difficult/gate issues/barely walk across the parking lot or up the stairs" and "unfortunately due to his gate issues, slip and hit his head" required physician office visit and emergency room visit. The patient underwent the following laboratory tests and procedures: Scan: Not reported. Therapeutic measures were taken as a result of head injury.  Clinical course: Caller is calling about the COVID-19 Vaccine. A couple years ago he took the shot and then had to get a follow up shot a month later. He was fine and light on his feet. Almost immediately after his 2nd shot, he had terrible slowing down, could barely walk, and now 2 years later, getting around is more difficult. He doesn't have the lightness of gate. These side effects are a real issues and he has never had a medical issue in his life and has caused him a tremendous change. He has seen a neurologist, heart specialist and spinal specialist and these specialist didn't see anything but did recognize the different. He is going to suggest this has to do with the vaccines. This vaccine is not a classical vaccine but mRNA based. He has suffered. This vaccine can have serious neurological affects. He was a PhD and has taught in various medical schools. 20 years at (withheld). He was considered a medical professional and was teaching medical students but he was not a MD or clinician. This was so sudden after his 2nd shot. He was running around and fine and quickly and tactfully had all these problems. He has gone to a Physical therapist and nothing seems to help. He received the vaccines because of the mandates. Consent to contact: Caller states yes and no as he was not sure. He states he guesses Pfizer could but he doesn't want to condone that. Full contact details: not provided. He is not getting any better and this is still a real problem and he is doing his best with this. Sometimes he can barely walk across the parking lot or up the stairs at the medical school. He is not immobilized and can still drive his car and walk down the hallway but this was a sudden onset thing. He went to a cardiologist, orthopod, and neurologist. The doctors recognized the problem but couldn't give him a differential. For him, if this all happened within a week of 2nd shot certainly 2 weeks. Caller is looking at his CDC Vaccination Record card. He likes Pfizer and has given talks at Alzheimer conferences and thought well of Pfizer. He had mixed feelings about the vaccine especially the 2nd shot. His work made him get the vaccine and was firing people. Nurses didn't want the shots and were quitting and being fired from their jobs that they loved. He hasn't taken medications never in his life, no illnesses or medications and never been in the hospital. He took a weight medication for a week and didn't like the medication. He eats healthy and is very careful. No heart problems. He only took the weight medication about 6 weeks ago and took 1 pill and the medication was from (withheld) and he didn't like the medication and threw away. His weight is good and decided to join a gym. He can sit down and do machines but can't run on the machines. He works at (withheld). People were just lining up and had to have a set times. He doesn't want to give a hard time. These side effects are real. He states the side effects are not real all the time but even his son and wife saw him slowing down and happened so quickly. Prior Vaccinations (within 4 weeks) If applicable, No any other vaccinations within four weeks prior to the first administration date of the suspect vaccine(s). AE require visit to Emergency room, he went to the Emergency room at (withheld). He did unfortunately due to his gate issues, slip and hit his head and had to get checked out and had a scan. He basically gave himself time and recovered from that. His gate just not what should be. He appreciates how nice and thoughtful this call handler is and doesn't have any particular issues about this. He wishes Pfizer was more transparent about Adverse Side Effect about these vaccines. He knows Pfizer was experimenting and learning on the go. He wants Pfizer to know that this has not been good for him. He asks will he ever hear anything about this.; Sender's Comments: Based on the available information in the case, the causal association between the events Gait disturbance, head injury  and the suspect drug  cannot be excluded.  The impact of this report on the benefit/risk profile of the Pfizer product is evaluated as part of Pfizer procedures for safety evaluation, including the review and analysis of aggregate data for adverse events. Any safety concern identified as part of this review, as well as any appropriate action in response, will be promptly notified to regulatory authorities, Ethics Committees, and Investigators, as appropriate.