unable to cognitively understand statements and speak sentences; unable to cognitively understand statements and speak sentences; i started having intense heart palpitations; light-headed; dizzy; Booster; I am unable to exert energy from my body without becoming light-headed and dizzy; This is a spontaneous report received from contactable reporter(s) (Consumer or other non HCP). The reporter is the patient.  A 36 year-old male patient received bnt162b2 (BNT162B2), administered in arm left, administration date 03Dec2021 13:00 (Lot number: FH8028) at the age of 36 years as dose 3 (booster), single for covid-19 immunisation. The patient's relevant medical history and concomitant medications were not reported. Vaccination history included: Bnt162b2 (Dose Number: 2, Batch/Lot No: EW0150, Location of injection: Arm Right, Vaccine Administration Time: 01:00 PM), administration date: 02Apr2021, when the patient was 35 years old, for Covid-19 immunization; Bnt162b2 (Dose Number: 1, Batch/Lot No: ENG6199, Location of injection: Arm Right, Vaccine Administration Time: 11:00 AM), administration date: 13Mar2021, when the patient was 35 years old, for COVID-19 immunization. The following information was reported: IMMUNISATION (hospitalization) with onset 03Dec2021 13:00, outcome "unknown", described as "Booster"; SPEECH DISORDER (hospitalization), COGNITIVE DISORDER (hospitalization) all with onset 15Dec2021 09:00, outcome "not recovered" and all described as "unable to cognitively understand statements and speak sentences"; PALPITATIONS (hospitalization) with onset 15Dec2021 09:00, outcome "not recovered", described as "i started having intense heart palpitations"; DIZZINESS (hospitalization) with onset 15Dec2021 09:00, outcome "not recovered", described as "light-headed"; DIZZINESS (hospitalization) with onset 15Dec2021 09:00, outcome "not recovered", described as "dizzy"; LOSS OF PERSONAL INDEPENDENCE IN DAILY ACTIVITIES (non-serious), outcome "unknown", described as "I am unable to exert energy from my body without becoming light-headed and dizzy". The patient was hospitalized for immunisation, speech disorder, cognitive disorder, palpitations, dizziness, dizziness (hospitalization duration: 1 day(s)). The events "unable to cognitively understand statements and speak sentences", "unable to cognitively understand statements and speak sentences", "i started having intense heart palpitations", "light-headed" and "dizzy" were evaluated at the physician office visit and emergency room visit. The patient underwent the following laboratory tests and procedures: echocardiogram: unknown result; electrocardiogram: unknown result; electrocardiogram ambulatory: wear a 48 hour holter monitor; magnetic resonance imaging heart: unknown results, notes: receive a cardiac MRI. Therapeutic measures were taken as a result of speech disorder, cognitive disorder, palpitations, dizziness, dizziness.  Clinical information: 12 days after vaccine, i started having intense heart palpitations, light-headed, dizzy, and unable to cognitively understand statements and speak sentences. This has not resolved in two weeks. This has caused me to have EKG's, Echocardiogram, be prescribed a beta blocker, wear a 48 hour Holter monitor and receive a cardiac MRI. I have seen my primary care physician and also an electrophysiologist, all who have confirmed this is likely from the booster shot I received. I am unable to exert energy from my body without becoming light-headed and dizzy, with palpitations following. No other vaccine in four-weeks and also no other medications in two-weeks. No covid prior vaccination and no covid tested post vaccination.  No follow-up attempts are possible. No further information is expected.