has had 4 very brief episodes of syncope in the past 4 days/ dizzy and passed out; Test: On monitor for 24hr w/ no, Result: Arrithymia; After each episode, she consistently describes dark and blurred vision for 15 min; arm twitching; then dizzy and passed out; she felt scorching hot for a few minutes; This is a spontaneous report from a contactable physician. A female patient of an unspecified age received second dose of BNT162B2 (PFIZER-BIONTECH COVID-19 mRNA VACCINE, Formulation: Solution for injection, lot number: EP6955 and expiration date were unknown), via an unspecified route of administration in arm right on 12Apr2021 as single dose for COVID-19 immunisation. Medical history included anxiety , depression from an unknown date and unknown if ongoing. Concomitant medication included escitalopram oxalate (LEXAPRO) taken for anxiety, depression from an unspecified date. Previously the patient received first dose of BNT162B2 (PFIZER-BIONTECH COVID-19 mRNA VACCINE, Formulation: Solution for injection, lot number: EP6955 and expiration date: 30Jun2021), via an unspecified route of administration in arm right on 22Mar2021 as single dose for COVID-19 immunisation.  It was reported that the patient who will be 20 years has had 4 very brief episodes of syncope in the past 4 days and spent 8 hours in ER Friday. Blood work, ECG, Echo, and MRI without contrast were normal. Doctors are baffled. Reporter enquired about the vaccine-related seizures 1 month after the second dose and asked for email address for a medical monitor supporting the vaccine trial. It was reported that the patient is perfectly healthy She does not drink or use any illicit drugs. She takes BCP to regulate her period and one month ago she started 5 mg/day Lexapro for test anxiety and COVID-induced depression. On Wed 12May2021 10 am while at work, she felt scorching hot for a few minutes, then dizzy and passed out; witnessed by 2 work colleagues. She will ask her colleagues tomorrow how long she was unconscious. On Thurs 13May2021 while at work she felt dizzy briefly but did not pass out. On Fri 14May2021 shortly after lunch while working in her cubicle, she woke up with computer keyboard imprint on her face. Unwitnessed, no warning whatsoever. Sat pm after dinner while in backseat of car, she felt dizzy and within a minute or so she had brief LOC lasting less than 1 minute. Sun 16May2021 after breakfast while bathing, she passed out. Unwitnessed. Her phone was nearby so she was able to call me. After each episode, she consistently describes dark and blurred vision for 15 min. Then she feels fine. No obvious seizure activity although last night her boyfriend said her right arm was twitching. No incontinence. Seen by her PMD on Thurs 13May2021 and we spent 8 hours at the ER Friday 14May2021: PE, orthostatics, CBC, Chem 18, pregnancy test, U/A, ECG, ECHO and MRI of brain without contrast was normal. No Neuro or cardiology consult (yet). Today her doctor is recommending she be admitted for observation, consults and further testing.  The patient has not received any other vaccinations prior 4 weeks and has no history of allergies. All tests done at the hospital came back normal. Daughter is currently in the hospital being discharged today 17May2021. She will wear a Holter monitor for 2 weeks to record any further events. Cardiology and neurology both conclude the adverse events were not cardio or neurological origin. Physician does not think it was seizures. She did not intend to report seizures-it was syncope. She does not have any further adverse events or history to report at this time beyond what she already reported.  The patient underwent lab tests and procedures which included blood test: normal, blood thyroid stimulating hormone: normal, electrocardiogram: normal, electroencephalogram: normal, investigation: normal, investigation: arrithymia, investigation: normal, physical examination: normal , pregnancy test: normal, urine analysis: normal on 13May2021, echocardiogram: normal, electrocardiogram: normal, full blood count: normal, investigation: normal, magnetic resonance imaging normal: normal on 14May2021. The outcome of the events was unknown.; Sender's Comments: As there is limited information in the case provided, the causal association between the events syncope, arrhythmia, dizziness, feeling hot, vision blurred, muscle twitching and the suspect drug BNT162B2 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.