dementia has gotten worse since he received the vaccine; violently explosive /he is having tantrums and rages; cognitive ability has decreased; violently explosive /he is having tantrums and rages; paranoid; This is a spontaneous report from a contactable consumer (patient's wife). A 68-year-old male patient received BNT162B2 (PFIZER-BIONTECH COVID-19 VACCINE, solution for injection), via an unspecified route of administration, administered in the left arm on 21Jul2021 at 16:00 (Batch/Lot Number: FA6780) (at the age of 68-year-old) as dose 1, single for COVID-19 immunization. There were no additional vaccines administered on the same date of the Pfizer vaccine. The patient did not receive any other vaccinations within four weeks prior to the first administration date of the suspect vaccine. Medical history included ongoing dementia with lewy bodies (diagnosed several years ago), liver transplant from 2009 (had the transplant due to Hepatitis C), ongoing diabetes (diagnosed prior to 2009), ongoing kidney disease (diagnosed sometimes after 2009), ongoing high blood pressure, ongoing depression (suffered from depression most of his life, hepatitis C, liver cirrhosis, trouble walking, muscle mass loss, and lost weight. The patient has trouble walking and muscle mass loss due to the dementia. The patient has lost weight due to diabetes, dementia and kidney disease and being a liver transplant patient. The patient had no family medical history relevant to the adverse events. Concomitant medications included tacrolimus (PROGRAF) taken for liver transplant from 2009 and ongoing; insulin glargine (LANTUS) taken for diabetes from an unspecified start date and ongoing (since before 2009); lisinopril taken for an unspecified indication from an unspecified start date and ongoing; carvedilol (COREG) taken for blood pressure high from an unspecified start date and ongoing; colchicine (COLCRYS) taken for gout from an unspecified start date and ongoing; allopurinol taken for gout from an unspecified start date and ongoing; celecoxib (CELEXA) taken for depression from an unspecified start date and ongoing; quetiapine fumarate (SEROQUEL IR) as antipsychotic from an unspecified start date and ongoing; mycophenolate mofetil (CELLCEPT) taken for liver transplant from 2009 and ongoing; donepezil hydrochloride (ARICEPT; reported as "Aracept") taken for lewy body dementia from an unspecified start date and ongoing (several years). On 21Jul2021, the patient experienced dementia has gotten worse since he received the vaccine, violently, and cognitive ability has decreased. On Jul2021, the patient experienced tantrums and ranges and paranoid. The reporter stated that her husband received the first dose of the Pfizer BioNTech Covid-19 Vaccine on 21Jul2021. She stated that almost immediately afterward he became "violently explosive" and has not improved since. The patient has a history of Lewy Body Dementia, diabetes, hepatitis C, kidney disease, liver cirrhosis, and he has had a liver transplant. The reporter stated that her husband's dementia has gotten worse since he received the vaccine, and he does not realize it. The reporter stated that he was having tantrums and rages, and that he has been paranoid after watching the news that if he and his wife are not fully vaccinated, they will get Covid-19 and die. The patient's wife asked, considering his health history and his reaction after the first dose, if he should get the second dose of the Pfizer BioNTech Covid-19 Vaccine. She stated that she will speak with her husband's transplant physician. The reporter stated she was not sure if the vaccine was even safe for him with his kidney issues due some of the inactive ingredients like sodium and potassium. She reported that her husband received on 21Jul2021 his first dose of the Pfizer Covid-19 vaccine. The patient has had a liver transplant, was diabetic, has severe kidney disease and Lewy Body Dementia, and immediately after the vaccine the patient has become very violent and has not changed since then. The patient got his vaccine at (withheld). The reporter stated the pharmacist lied to them. She asked him if the Covid 19 vaccine was approved by the FDA and he said yes but she was reading it was only approved for the emergency authorization use. She was afraid for him to have the second dose of the vaccine. She reported that the patient has lost weight due to diabetes, dementia and kidney disease and being a liver transplant patient. He has gotten more and more violent, dementia has worsened, he wants to just argue. She reported that he also has gout, states he has trouble walking and muscle mass loss due to the dementia, becomes violently explosive if he is out in public around a lot of people. The events did not require a visit to emergency room and physician office. There were no relevant tests. The outcome of the events was not recovered.