Seizures; Hallucinated; Diagnosed with metabolic encephalopathy; Her thyroid was low; Quit breathing for a short period of time; Memory loss; Not stable on feet; Can not write as well; Anger quickly; She feels old; Heart rate really low; balance issues; Fell out of bed unconscious; This is a spontaneous report from a contactable consumer (patient). A 71-year-old female patient received first dose of bnt162b2 (BNT162B2), via an unspecified route of administration on 26Mar2021 (Batch/Lot Number: ER8732) at age of 71-year-old as single dose for covid-19 immunisation. The patient was going to be 72, had been cooking, normally she weighs less, she was 168, she was 5'4" but lost an inch from getting older and her bones have compacted so now she is 5'3". No prior vaccinations within four weeks prior to the first administration date of the suspect vaccine. Medical history included Stage 3 kidney problems (They hydrated her enough in the hospital that she is stage 2 now and drinking lots of water), both knees done from Jul2018, depression (her son died and she has periods of depression, she has been on for about 20 years), breast cancer (about 6 year), swelling in her ankles, food in the esophagus, sinus (had sinus drainage) and being hoarse (from sinus drainage). Concomitant medications included sertraline taken for depression; letrozole taken for breast cancer; triamterene taken for swelling in ankles (had been on for less than 20 years); omeprazole taken for food in the esophagus. Caller confirmed she was calling about the Pfizer Covid-19 Vaccine, the first one. She had a severe reaction back in Mar2021 and her doctor told her to report it. Caller stated she got her vaccine around 2 or 2:30 in the afternoon on 26Mar2021. Caller had the first vaccine on 26Mar2021 and had not up until then changed anything in routine and had her shot, then 3 am the next morning (27Mar2021) she fell out of bed unconscious. Her sister could not arouse her, she didn't remember any of it. Her sister called an ambulance and they took her to Medical Center, the usual hospital she goes to. An ambulance came. They sent her through the Emergency room then upstairs. First, neurology ICU and then she went into seizures 2 or 3 times. Pretty soon after she was admitted to the hospital, maybe 3 days or so, she was sitting and had them twice. She did not know if they started in the ICU that was when they sent her to the Neurological ICU. Seizures started one day and she started shaking. For event quit breathing for a short period of time, caller stated she was told this happened. Seizures ended and the other stuff she was tested for everything but they could not find anything. When she started seizures, they sent her to neurological intensive care unit. Caller did not know exact dates of events or hospital stay except that she was unconscious the early morning of 27Mar2021 and then stayed in the hospital for 14 days. She went home that next Monday (11Apr2021), around 15 days later, but she is not sure. Caller did not remember any of this or when events occurred. The doctor told that she was very sick. She did not remember a lot of it truthfully and she had side effects, she thought her sinuses are not unusual. Caller had a little memory loss and she was not stable on her feet as she used to be. She moved over there because her sister needed someone to take care of or watch her. She was on three anti-seizure drugs now. When she first became unconscious, she could not tell what happened the first day or so. She caller her sister and told her that her life was in danger from the nurse there. She hallucinated. She thought some friends lives were in danger. She was in the neurological ICU at that time. The nurse said it was ICU delirium. People came to see her but she has no memory of this. The whole thing she was not aware of and one day the nurse told her she was in Hospital and that was her first memory she has but not before. She was still experiencing memory loss but not as bad. If her sister told her something she would not remember or what she just said she would not remember sometimes. It was better than when it was in the hospital but she was on medications. The patient could not write as well, her writing was terrible, very horrible. She was 71 and thought she was in good health before this happened. She had to write checks after the hospital and had to void them, so this happened pretty recent out of the hospital.  Call stated she overreacts to things and angers quickly. She was over-reacting to things but it was hard to say when it started. She snaped at her sister not like she hit her or anything just words were said between them and her sister has been patient with her considering she was not the best patients. She got angry at the doctors office when he and his nurse kept looking at her sister and thought maybe it was because they knew she had memory troubles. She overreacted. She felt old, 71 was not young. Her family lived until their upper 80s and 90s which was older. Not everybody, but a lot had lived to be that old. She had balance issues started in hospital, they would not let her get up and go to the bathroom by herself. She has had balance issues since then. Quit breathing for a short period of time: they told her this but she did not know, maybe it was in the emergency room and was pretty quickly. She was admitted on 27Mar2021. Patient also had heart rate really low, caller added this occurred around the time of her breathing, it became shallow around that time. She did not know but there were three anti-seizure drugs. Her primary said he had never seen that many that anybody was on. Caller did not know additional information. She will see the neurologist 28Jun2021. She still felt like she was coherent now that she can make a sentence. Caller added she did not know which arm she got the vaccine in. Her doctor told her not to take the second one. Patient was diagnosed with metabolic encephalopathy, caller did not know additional details, caller stated her pills were upstairs and she did not want to get them right now. She was taking herbs and nutrients. Investigations showed thyroid was low. She had a brain MRI, and checked her heart. Both were clear. She did not know details. Caller stated somebody said she had a good physical. It was while in the hospital. Her sister said she was hooked up to everything at first. They drew blood not long ago when she went to primary care physician for testing. She was on levothyroxine which was a thyroid drug. Her thyroid was low. She was taking her thyroid medicine to keep her thyroid up to normal. Caller confirmed this was after the vaccine. Dr. told her not to get the vaccine again, she reported this to pharmacy headquarters and gave them dates and numbers. Caller did not know which arm she got it in. She did not feel safe being by herself and that may change. She has never had a reaction to anything, she is not allergic to anything. She can believe the vaccine had something to do with this and played a part to her hospitalization and symptoms.  It was too close together that afternoon 2 or 2:30 to less than 12 hours the next morning. The first she said was at 9 she said but it was 12 hours later. Caller does not clarify statement. She knows she should not get on the internet but she was on a medical web resource and they reported that the rate of being diagnosed with fatalities was 23% would survive in the 1st year, then during follow up 5 years was 47% and it scared her to death. The majority of people would be dead 1 to 5 year follow ups. This was off the internet. Her doctor said she was not in danger of dying. That was emotionally traumatizing that she would die and went to the hospital and when she was unconscious she thought she was going to die. She went to the hospital and it was traumatic, it changed her life completely. The outcome of events was unknown.  Follow-up attempts are needed. Information on the lot/batch number has been requested.