Sudden cardiac arrest; This is a spontaneous report received from a contactable reporter(s) (Other HCP).  A 29 year-old female patient received bnt162b2 (COMIRNATY) (Batch/Lot number: unknown) as dose 2, single for covid-19 immunisation. The patient's relevant medical history and concomitant medications were not reported. Vaccination history included: Covid-19 vaccine (Dose: 1, MANUFACTURER UNKNOWN), for Covid-19 immunization. The following information was reported: CARDIAC ARREST (medically significant), outcome "unknown", described as "Sudden cardiac arrest". Reporter states she been on the COVID unit since the beginning. She has contacted Pharmacists about these vaccines and they keep saying they are just administering them. She didn't see this in 2020, but she has been seeing a lot this year of injuries and people getting hurt and dying. Now it's happening to the reporters own family and friends including her grandmother. The caller was told to call Pfizer. The reporter states in 2020, some of the nurses were off and didn't have hours because the hospitals were empty and was a designated COVID hospital so if someone had issues they are to come there. She knows they were saying COVID causes heart attacks and COVID lung, so she didn't jump to conclusions. However, now after the vaccines, she was seeing people get sick. She was seeing people get streptococcal pneumonia right after the shots. They were saying its COVID but they do extensive testing and see its either a bacteria pneumonia or streptococcal pneumonia. She clarifies her facility does the PCR COVID test and have to send it off where its like a 30 panel test, and nobody comes back positive for COVID. The caller states this has going on in the hospital and now its family members and coworkers. She states her mother and boyfriend are reports. Her neighbor is a report. Her grandmother is in the hospital. When asked to complete a report on all of these individuals, the reporter states all of it has already been reported. She knows her neighbor has been already reported. Her neighbor went into sudden cardiac arrest the night after she got her second Pfizer shot. Her neighbor is 29-years-old. All the vaccines have the same effects in what she is seeing in people. She wouldn't be able to tell a difference in which vaccine it was. The patients are all having the same side effects with different vaccines. Reporter confirmed she doesn't have specific NDC, Lot and expiry dates to provide for any manufacturers at the time of the call, but she has all the information and the charge nurse at the hospital has it. They have been keeping track of this for a while now. This information can be sent if needed via email.   The lot number for bnt162b2 was not provided and will be requested during follow up.; Sender's Comments: Based on the available information, there is a reasonable possibility of a causal relationship between the suspect vaccine BNT162B2 (COMIRNATY) and reported event cardiac arrest. which cannot be fully assessed/excluded. The case will be reassessed if additional information becomes available. 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.