she is having confusion and dementia,; went into this kind of like dementia-like state where she talked incessantly/ she is having confusion and dementia,; She had days of vomiting and nausea; She had days of vomiting and nausea; She complained of brain fog and couldn't focus on the tv or her programs; kidney functions were not good enough; she has mood swings; she could not remember or know everything from the present; she had a UTI; This is a spontaneous report from a contactable consumer (patient's sister). A 68-year-old female patient received the second dose of BNT162B2 (PFIZER-BIONTECH COVID-19 VACCINE), via intramuscular injection on 20Jan2021 (at the age of 68-year-old) at single dose for COVID-19 immunisation. Medical history included ongoing breast cancer stage IV, patient was in treatment for breast cancer stage IV, she had cancer 13 years prior the report in 2008, and then was found again and diagnosed 3 years prior the report, in Jun2018; chronic obstructive pulmonary disease (COPD), a long time, a lot of her adult life. The patient was on oxygen; she had a lot of fluid built up from the cancer; patient tested positive for COVID in 2020 (Feb2020 or Mar2020, as reported). She and her roommate tested positive and had a cough. They had no fever or other symptoms. Both in the nursing home got over the cough and 21 days later tested negative. Patient tested negative for COVID ever since. The nursing home tested the residents and staff every week. They had tested the patient so much to the point her nose was bloody which the reporter got upset about; hallucinations and paranoid thoughts. Concomitant medications included ongoing perphenazine (TRILAFON) taken for hallucinations and paranoid thoughts; treatment for breast cancer stage IV and oxygen. The patient lived in nursing facility and had received both Pfizer vaccine doses. The patient received the first vaccine for COVID-19 immunisation in Dec2020. She was fine. She got the second one on 20Jan2021. Since patient received the 2nd vaccine dose, in Jan2021, she was having confusion and dementia, which was not an issue before the vaccine doses. The patient was having trouble putting words together. Patient initially had vomiting, nausea and brain fog where she could not concentrate on her TV, in Jan2021. She was hospitalized from 17Feb2021 to 20Feb2021 to have all kinds of tests run and see if her cancer had spread to her brain. Patient had 3 years with stage 4 breast cancer and had fought so hard and was aware of her confusion and it was very upsetting to her. She had days of vomiting and nausea. She complained of brain fog and could not focus on the tv or her programs. Within days, she went into this kind of like dementia-like state where she talked incessantly and could not get a thought completed. Patient would go from one thought to the next. It was very bizarre. She had never had this kind of issues. This went on for so long, they finally put her in the hospital. Patient had stage 4 breast cancer, and the doctors thought maybe her cancer had gone to her brain. The doctor did not think it was related to the COVID-19 vaccine. She was checked for a urinary tract infection (UTI), for brain cancer, for a stoke, for everything. She saw so many doctors. She still had not come out of this a month later. She was currently on psych meds because she had mood swings, since Jan2021. It had been one thing after another. The patient could not tell the time. On some level, patient knew something was wrong. She was in a very confused state. She did not know how to tell anyone what she wanted to tell. It was very distressing to say the least. She had made a little bit of progress. She could tell time with some struggling but she got upset and cried. Patient could only tell that the time was 3, but not 3:15. But, then she cried and got upset. She had been able to tell time a couple of times, but if you asked her what day was it, she had no clue. She had no clue what day it was and would ask "what day is it?" Her moods all over the place. The patient was still very confused. The reporter explained the patient could be 5'3'', she was unsure. The reporter really did not know the patient weight, she was guessing around 270lbs. She had a lot of fluid built up from the cancer, and reporter had not seen her since COVID started. Patient told that her weight was up around 300lbs. The reporter declined to include a healthcare professional for the report, stating she had not spoken to her sister's primary care doctor. She was waiting for her to call back. The patient was sent to the ER and admitted into the hospital on 17Feb2021. She came back from the hospital on 20Feb2021 at 6:30pm. She had a CAT scan, MRI, bloodwork done, in Feb2021. She saw a psychiatrist, neurologist, her oncologist. There was so many doctors seeing her and talking to the reporter. The last doctor the patient saw in the hospital said that she thought the patient was dehydrated from her vomiting episodes, but did not know for sure. In Feb2021, the nursing home did blood tests and a urinalysis to see if she had a UTI. The blood work would have shown if patient was dehydrated and she was not. The head nurse thought it was the vaccine, but she was not sure. Everybody was not sure. No one could tell her anything concrete about patient. She was not normally like this. Patient had recovered completely from the nausea and vomiting. They tried for a while to give her an anti-nausea medicine, but she could not keep anything down. It was given to her orally, she did not know why an injection was not given. This lasted for a few days, clarified as maybe 3 days. The reporter had no name, NDC, lot number or expiry date for the anti-nausea medicine the patient took. She knew it was given to her once and when they tried to give it to her again, patient refused. Reporter had no product information to provide for the first and second doses of the COVID-19 vaccine, did not have the patient vaccine record card. This would be with the nursing facility. She mentioned patient went into the nursing home on Jan2018 and then was diagnosed with breast cancer Jun2018. She did not know if there were any interactions there with the patient having the breast cancer and receiving the COVID-19 vaccine. The reporter had no product information for the first dose. When probed for the date in which the first dose was given, she explained she was sent constant emails which could have provided a date, but she did not know this information offhand. It was approximately a month before the second dose, or it could have been on 27Dec2020, which was a little closer than a month apart. No additional vaccines were administered on the same date of the Pfizer vaccine. The events required a visit to emergency room. Patient had constant testing while in the hospital. In the hospital, in Feb2021, they did MRI and CAT scan to see if the breast cancer had gone to the brain and both were negative. They tested for UTI. They did the first UTI test at nursing home in 2021 and they said she had a UTI and patient was put on an antibiotic. They tested her again for a UTI when she was admitted into the hospital in Feb2021 and they said she did not have a UTI. She did have a buildup of urine in her bladder because her kidney functions were not good enough for the MRI at first, in Feb2021. Her bladder was relieved of the urine build up and her kidney functions improved and she was able to get the MRI. The MRI did not show any cancer in the brain. None of it relieved her symptoms. This was just bizarre. It happened within a week of receiving the vaccine. She could not talk with patient and patient had never been like that. The patient had always been lucid and open and you could talk about anything: the past, the present, she had no problems. She could remember everything crystal clear from the past but she could not remember or know everything from the present. The reporter would ask her what day was it and the patient did not know. The patient would absorb the information she was told but there was like this strange disconnect, almost like a dementia of some form. About concomitant medications, the reporter explained the patient had not started anything new. She had been on the same stuff for many years. She had psych meds that she had been on, but she had been on those for many years. She clarified further that patient had been stable on her psych meds for many years, and the nursing facility had the patient stable for 3 years at the nursing home. At the time of the report, her mood swings were all over the place, she had never had that before. She had hallucinations and paranoid thoughts in the past, but she had never had mood swings like this and never had dementia. She had been on the same medications for a long time, but they were currently trying to play with them and trying to adjust her psych meds. It was apparent it was not working and this was something more organic, something going on in her body. The psych med was perphenazine all of her life. The psych nurse was a new nurse and was not familiar with the patient. The psych nurse informed the reporter she raised the perphenazine to the highest dose she could possible go on and told she could have to try the patient on a mood stabilizer and could have to put her in a psych unit. The reporter would not have any NDC, lot numbers or expiration dates, or anything like that. The reporter had been told an UTI could have caused the patient symptoms. It could have been brain cancer, or this or that. She did not know what was going on. Reporter asked if there had been any reports or had other people called in with these types of reactions or adverse events. The patient had recovered from vomiting and nausea on an unknown date in 2021, had recovered from kidney functions were not good enough and UTI in Feb2021, the outcome of the other events was unknown.  Information on the lot/batch number has been requested.