thought it may be a blood clot; Head numbness; nausea; vertigo; balance disturbances; Sensation of a runner's high/runner's high - kind of like he has drunk two beers all the time; This is a spontaneous report from a contactable pharmacist (patient). A 58-year-old male patient received BNT162B2 (PFIZER-BIONTECH COVID-19 VACCINE), (at the age of 58 years old) via an unspecified route of administration, administered in Deltoid Left on 2021 (approximately 8 months ago) (Batch/Lot number was not reported) as dose 2, single for covid-19 immunisation. The patient has no medical history. Concomitant medication included aspirin [acetylsalicylic acid] (ASPIRIN [ACETYLSALICYLIC ACID]). The patient had the first single dose of BNT162B2 (PFIZER-BIONTECH COVID-19 VACCINE) on an unspecified date for COVID-19 immunization. The patient received the second dose of the Pfizer BioNTech Covid 19 vaccine approximately 8 months ago but doesn't know the exact date. Since then, he has been experiencing nausea, vertigo, balance disturbances, head numbness and sensation of a runner's high - kind of like he has drunk two beers all the time. He stated that it hasn't affected his ability to work in retail or play guitar, but he is still having these side effects 8 months later.  He has taken meclizine, but it hasn't helped. He does sometimes take Zofran for the nausea. The patient clarified that there is no tinnitus, only vertigo. The patient mentioned that when the vaccine came out, they all shot each other regarding giving each other the vaccine and after his 2nd shot he had nausea and vertigo and here he is 8-10 months later and he still has the nausea and it comes and goes a little bit ever since and also has a balance disturbance and it is a slight or ever so slight balance disturbance and the only way to explain it is he has a runner's high all the time and he used to be a runner and this feels like a runner's high and thought it may be a blood clot but he has no other symptoms other than a very slight balance disturbance and numbness in his head that does not affect his cognitive ability. He has not shared this information with anyone at work and does not want to freak people out and can't imagine how many shots he has given, and he is pro vaccine and would not be here today without vaccines, but nothing is 100 percent.  The reported events are persistent and feels like the nausea has not resolved. It has been 10 months when the first couple of symptoms occurred and it does not affect his daily living and is literally like he is feeling like he ran a massive run, and it is a great feeling not a bad feeling but definitely noticeable. The patient declined to provide further HCP contact information and stated he has not been to his doctor in about a year and did not see the doctor after this happened but went to urgent care a couple of times and took Zofran 4mg tablets and was fine and took a half tablet in the morning and was fine. He still works 50-60 hours per week sometimes and kept this information to himself and the nausea is not going away and comes and goes. He can't remember the exact dates the symptoms began or when his Pfizer COVID Vaccine 1st and 2nd doses were; the exact date was a month after the shot was available. He was told he did not have any type of stroke and noticed no changes in his manual dexterity and would have noticed that. After his 2nd dose, he woke up the next morning and had vertigo and nausea and did not think much of it that happens after shots and primarily this has stopped now, and he has vertigo once in a while. He has a very small mobility balance, and it is not the same as it was and has the feeling of runner's high that is slight and did not resolve and is annoying and definitely something that does not affect his daily life at all and felt like he drank two beers all the time not to mention impairing slightly like a runner's high. He is unsure of the reason for this or if a plaque may be stuck in his blood stream flow or artery and thinks he will do screening for that. He started taking Aspirin 81mg every day for a couple of weeks to see if there was a blockage and it did not do anything; it did not seem like he had a blockage and does not know the root cause of this and took the Pfizer COVID Vaccine to not get covid and ever since has bouts of the nausea and balance issue that is not the same and feels like he has a runner's high; states he has no symptoms of stroke or problems with manual dexterity and before school he was a guitarist and that is unaffected. The patient stated that there is a good probable cause that his reported events are caused by the Pfizer COVID Vaccine as it all started after his 2nd dose. The outcome of the event clot blood was unknown while the other events were not recovered.  The lot number for BNT162B2, was not provided and will be requested during follow up.; Sender's Comments: Based on the description given in the narrative, there is reasonable possibility of causal association between the serious events Thrombosis, Hypoesthesia, Nausea, Vertigo, Balance disorder, Feeling drunk and the suspect BNT162B2 cannot be excluded. The impact of this report on the benefit/risk profile of the Pfizer drug 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.