she slowly declined with pneumonia; Woozy/Dizzy; Sleeping all the time; Not eating; Running a fever off and on; Her blood pressure was a bit low, 105 over something; suspected COVID-19 with symptoms; Heart attack; This is a spontaneous report from Pfizer from a contactable Consumer reported for mother. A 65-years-old female patient received bnt162b2 (BNT162B2), dose 1 via an unspecified route of administration on 05May2021 as 1ST DOSE, SINGLE for covid-19 immunisation. The cancer doctor told her that she needed a Covid vaccine since she has cancer and a lowered immune system. Medical history included Metastatic rectal cancer from Jul2019 to 17May2021, Osteoporosis from unknown date to 17May2021 (She had it for maybe 10 years or something), Fibromyalgia from unknown date to 17May2021 (She had the fibromyalgia for 20 years). She had rectal cancer, osteoporosis, fibromyalgia, and a couple other things that the caller can't think of off hand. Her mother was diagnosed with the rectal cancer in Jul2019. The caller has no idea when she was diagnosed with the osteoporosis. She had the fibromyalgia for 20 years, and the caller is sure it was the same for the osteoporosis, maybe 10 years or something. They were being managed. There were no concomitant medications.  The patient did have metastatic rectal cancer, but it was managed. She was not on hospice or terminal, and they hadn't exhausted all of the treatment plans yet. It was being controlled. She was under the surveillance of a cancer doctor who was completely shocked by her sudden death. It seemed like there was no reason. She was fine and drove herself to her appointments all the time. She had just driven herself to her last appointment. She passed away yesterday morning. She was slowly declining since she got the vaccine. The coroner was playing guessing games and assumed it was pancreatic cancer. Well, she didn't have pancreatic cancer, and the doctor already said the cancer didn't kill her. The doctor said if he had to guess it could have been some kind of pneumonia or a reaction to the vaccine. All of it made her heart stop. The coroner couldn't get the city to approve an autopsy to see the real cause of death because there was no foul play. The caller took it upon herself to discover if maybe Pfizer could help, and she needs to alleviate the vaccine as an option if it contributed. She is so tired and hasn't slept. It is devastating. This woman was everything in her life, and the caller is probably going to go next with how she feels. She feels responsible. Her other guess is if she gave her mother Covid and she slowly declined with pneumonia. The caller couldn't get her sister to take her mother to the ER. Her sister was there Sunday night. On Monday morning her sister called to say her mother was gone. On 05May2021 the patient had the first dose of the Covid vaccine. The caller could have gone there or called an ambulance when her mother wasn't answering the phone. She knew something was wrong. She called her sister who said their mother wasn't feeling good. Her mother was woozy, dizzy, and sleeping all the time. On day 3, Sunday, the caller couldn't get her mother on the phone. She thought she had some level of peace because her sister was there and could keep her updated. Her mother often gets sickly, but she always answers the phone even if she is deathly sick. The caller thought enough is enough and she needed to be put on the phone on speaker with her mother. The caller's sister said her mother was sleeping. The doctor said to probably bring her mother to the ER. The caller told her sister who just didn't take her mother to the ER. The caller could have called an ambulance. She feels incompetent. They are assuming the cause of death was a heart attack. If her mother had gone to the ER on Sunday night they may have found out. Her mother became woozy last weekend because the caller was there on Thursday and her mother didn't look good. She had her chemo bag because she brings it home. It was her first new chemo treatment, and the caller had never seen her mother respond like this. It was strange. Any other time when she was getting chemo she felt great because there is so much stuff in there like steroids to prevent a reaction. It was surprising because she was only sick on chemo once and she had been on this one before. She was just off. Then she continued to decline from there. It started before the chemo. She got on chemo that Thursday before Mother's Day, she was on her first chemo treatment at that time. She was sick a couple of days before that. She had the chemo on 06May2021. She started feeling sickly the day she got the injection on 05May2021. When the caller was there she was thinking it was from the chemo. The caller calls her mother every day and she was sounding worse and worse. On Thursday 13May2021 her mother took herself to her chemo follow up appointment and was telling the doctor that she was woozy, dizzy, and not eating. The doctor gave her fluids, and he didn't give her chemo because she was not scheduled for it that day. It was just a follow up appointment. He sent her home. The caller talked to her mother on Thursday evening and she didn't sound good and told her she was woozy and dizzy. On Friday, Saturday, and Sunday she didn't answer the phone. The caller's mother is totally against vaccines, and she had been begged to get the pneumonia and flu vaccine and denied them. She had never responded well to them in her life. Even as a cancer patient they would say she needed it and she wouldn't. She did get the Covid vaccine even though she didn't want to. The caller thought her mother was trying to convince herself it was because of the vaccine because she is so against them, but now she doesn't know. The doctor said he didn't think it would have been Covid because she didn't have a fever. Her mother told her that she had been running a fever off and on, which is not unusual for her mother. The doctor didn't think it would have been Covid. Her mother started sleeping all the time mid week last week. She started not eating at the end of last week. The caller has no idea when her mother had a fever. She hadn't gotten to talk to her mother all weekend. At some point last week her mother had said in a conversation that she had a fever off and on. Then on Thursday when she went to the chemo doctor she had no fever it shows it was 97 something. Her oxygen was fine. Her blood pressure was a bit low, 105 over something, which is low for her. She didn't have a fever last Thursday. Prior Vaccinations within 4 weeks no other vaccinations. Blood work on 13May2021 with unknown result. The patient passed away on 17May2021 after receiving the first dose of the Pfizer Covid vaccine. The caller expresses concern that her mother may have had Covid. No autopsy done. Cause of death was Heart attack.  Information on Lot/Batch number has been requested.; Reported Cause(s) of Death: Heart attack