Pain; Tightness in chest; having pounding and an irregular heartbeat/she could feel it pounding outside of her body; Booster; severe headache; trembling all over; weakness; Dizziness; having pounding and an irregular heartbeat/booster brought it back to a high level; had a weird feeling; she was so sick; it is like if you are coming down with bronchitis; later on a cough loosens; pain is all over caller's legs, arms, and torso and is persisting; This is a spontaneous report received from a contactable reporter(s) (Other HCP) from medical information team. The reporter is the patient.  A 74 year-old female patient received bnt162b2 (COMIRNATY), administered in arm left, administration date 13Jan2022 10:08 (Lot number: FE3594) at the age of 74 years as dose 3 (booster), single for covid-19 immunisation. Relevant medical history included: "Diabetes", start date: 2014 (ongoing); "Immunocompromised" (ongoing); "She has had irregular heartbeat intermittently in the past but it was not serious" (unspecified if ongoing). There were no concomitant medications. Vaccination history included: Bnt162b2 (First dose, lot: EL3249, Route of administration: left arm), administration date: 20Jan2021, when the patient was 73 years old, for COVID-19 Immunization, reaction(s): "did not have any reaction at all"; Bnt162b2 (Second dose, lot: EL9267, Route of administration: left or right arm, doesn't  remember which arm), administration date: 10Feb2021, when the patient was 73 years old, for COVID-19 Immunization, reaction(s): "did not have any reaction at all". The following information was reported: IMMUNISATION (medically significant) with onset 13Jan2022 10:08, outcome "unknown", described as "Booster"; HEADACHE (disability) with onset 13Jan2022, outcome "recovered" (14Jan2022), described as "severe headache"; TREMOR (medically significant) with onset 13Jan2022, outcome "recovering", described as "trembling all over"; ASTHENIA (disability) with onset 13Jan2022, outcome "not recovered", described as "weakness"; PAIN (medically significant) with onset 13Jan2022 11:00, outcome "not recovered", described as "Pain"; CHEST DISCOMFORT (medically significant) with onset 13Jan2022 11:00, outcome "recovering", described as "Tightness in chest"; DIZZINESS (disability) with onset 13Jan2022, outcome "recovered" (14Jan2022), described as "Dizziness"; HEART RATE IRREGULAR (medically significant) with onset 13Jan2022, outcome "recovering", described as "having pounding and an irregular heartbeat/booster brought it back to a high level"; PALPITATIONS (medically significant) with onset 13Jan2022 11:00, outcome "recovering", described as "having pounding and an irregular heartbeat/she could feel it pounding outside of her body"; FEELING ABNORMAL (non-serious) with onset 13Jan2022, outcome "unknown", described as "had a weird feeling"; ILLNESS (non-serious) with onset 13Jan2022, outcome "recovering", described as "she was so sick"; BRONCHITIS (non-serious) with onset Jan2022, outcome "unknown", described as "it is like if you are coming down with bronchitis"; COUGH (non-serious) with onset Jan2022, outcome "unknown", described as "later on a cough loosens"; PAIN IN EXTREMITY (non-serious) with onset Jan2022, outcome "not recovered", described as "pain is all over caller's legs, arms, and torso and is persisting". The events "having pounding and an irregular heartbeat/booster brought it back to a high level" and "having pounding and an irregular heartbeat/she could feel it pounding outside of her body" were evaluated at the emergency room visit. The patient underwent the following laboratory tests and procedures: heart rate: (13Jan2021) irregular.  Clinical Course: The caller reported that her and her husband had the first two Pfizer Covid vaccines, and they were fine. They got the Pfizer booster dose yesterday and they had severe reactions that were terrible, and they still have some residual left today. She was shocked after receiving it because the first two were fine. She stated she has diabetes and was immunocompromised. Due to heart conditions, she was having pounding and an irregular heartbeat. She stated she does not have a heart condition and the vaccine did this to her. She has had irregular heartbeat intermittently in the past, but it was not serious. The booster brought it back to a high level where she could feel it pounding outside of her body. She stated her husbands temperature was higher yesterday and he was very sick also. She stated she went to the ER yesterday but so many people were in there and she was so sick that she could not sit up, so she left to go home and get in bed and did not get seen. She stated she wished she had been seen. She stated it is a little better today. The caller states the Pfizer Comirnaty Covid Vaccine effected the callers nervous system. The caller was trembling all over, heart pounding, severe headache, weakness, and dizziness. The caller was trembling all over. The caller received the booster dose Pfizer Comirnaty Covid Vaccine at 1030 on 13Jan2022 and had a weird feeling 10 or 15 minutes later and at about 1100 on 13Jan2022 the caller had everything, pain, tightness in chest, heart pounding. Heart pounding: The caller could feel heart beating. The caller had irregular beats. The caller clarifies everything advanced and was not all at once, advanced as it got later in the day on 13Jan2022. Caller clarifies severe headache, weakness and dizziness all started on 13Jan2022. Everything the patient had occur began on 13Jan2022.trembling all over: The caller states the trembling all over is still occurring slightly but is not as bad. heart pounding: The caller states the heart pounding continued on until the caller went to sleep at 2200. The heart pounding went away today, 14Jan2022. asks if caller recovered completely or with lasting effects from heart pounding and the caller replies, the caller can still feel heart beating, do not usually feel heartbeat, can still feel somewhat. severe headache: When the caller awoke this morning, 14Jan2022 the severe headache was gone. The caller went to sleep on 13Jan2022 with the headache. The caller has recovered completely. weakness: The caller still has weakness, and it is persisting. dizziness: When the caller awoke this morning, 14Jan2022 the dizziness was gone, and the caller recovered completely. pain: The pain was all over caller legs, arms, and torso and is persisting. tightness in chest: The tightness in chest is still going on. The caller would like to explain that it is like if you are coming down with bronchitis and have a tightness in chest and later on a cough loosens. The tightness in chest is improving. irregular beats: The caller has a stethoscope because the caller was nurse, but the caller has not checked the irregular beats this morning, 14Jan2022 and cannot really say if still ongoing. Seriousness criteria: irregular beats: The caller thought irregular beats was serious, could have been myocarditis is what caller is thinking. No other vaccinations within four weeks prior to the first administration date of the suspect vaccine and no AE(s) following prior vaccinations.; Sender's Comments: Based on the current available information and the plausible drug-event temporal association, a possible contributory role of the suspect product BNT162B2 to the development of events cannot be totally 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.