Lost his ability to think, walk and talk; Lost his ability to think, walk and talk; Lost his ability to think, walk and talk; Seizure; Autoimmune Encephalitis; swelling of brain; tired; This is a spontaneous report from a contactable consumer. This consumer (patients wife) reported for a 51-year-old male patient that:   A 51-year-old male patient received bnt162b2 (PFIZER-BIONTECH COVID-19 VACCINE, Solution for injection, Batch/Lot Number: ER8727, Expiry date: unknown), dose 1 via an unspecified route of administration, administered in Deltoid Left on 25Mar2021 (at the age of 51 years old) as dose 1, single for covid-19 immunization at hospital. Medical history included Stroke from 2009 and Seizures. The concomitant medications were not reported. The patient also received second dose of bnt162b2 (PFIZER-BIONTECH COVID-19 VACCINE, Solution for injection, Batch/Lot Number: EW0187, Expiry date: unknown), via an unspecified route of administration, administered in Deltoid Left on 10Jun2021 as dose 2, single for covid-19 immunization and experienced similar events. History of any previous immunization with the Pfizer vaccine considered as suspect was not provided. No additional vaccines administered on same date of the Pfizer suspect. Adverse event required a visit to Emergency Room/Physician Office. No vaccinations (within 4 weeks) prior to the first administration date of the suspect vaccine. No Adverse events following prior vaccinations. No relevant medical history (including any illness at time of vaccination). No relevant family medical history to adverse event. Relevant tests done included many tests which were negative except one which was positive was the IGG immunoglobulin. The patient experienced lost his ability to think, walk and talk on 07Apr2021 slightly before 18:00, but late afternoon, seizure on 05Apr2021 18:00, autoimmune encephalitis, swelling of brain and tired on an unspecified date in 2021. The patient was hospitalized for lost his ability to think, walk and talk from 07Apr2021 to 28May2021. The patient was hospitalized for seizure from 05Apr2021 to 07Apr2021. When he went to the ER the first time for the seizure, he got treated and released and by Wednesday, he had other symptoms and had to go back. His doctors told the seizures will be an indefinite condition that he was going through and the treatments will be indefinite. He won't recover 100%. He got his second vaccine on 10Jun2021 per recommendation from his neurologist. He was hospitalized again on 17Jun2021, and then said it was 18Jun2021. Reason for this hospitalization was again because of his inability to speak, walk and think. He could not tell his name, address, date of birth or things. He had a doctor's appt that day as well. He was able to walk with help now, where as before, he could not walk. He was still getting Physical Therapy. He was still having trouble with speech. He got speech therapy. With everyone helping, he was getting better. He had to get on a regimen where he got an infusion every 6 months and that was what will keep him alive. The infusion was Rituximab, and he was due for next treatment 01Nov2021. Recurrent seizures hospitalization was for 2 weeks. She then later corrected to discharge on 16Sep2021. Adverse event resulted in visit to Emergency room on 05Apr2021 and back on 07Apr2021. He was treated for seizure and released on 05Apr2021. On 07Apr2021 he was admitted because he lost his ability to think, walk and talk. She took him back to the same ER on 18Jun2021 with same inability to think, walk and talk. He was admitted for the same. Adverse event resulted in visit to Physician Office. When he got out the first time, he saw his primary care and then he had an autoimmune visit with autoimmune neurologist. He was giving the Rituximab infusion every 6 months. He had an endocrinologist now because of all the steroids given in hospital and now, he had steroid induced diabetes. Whatever they gave in the hospital was unknown. She knows it was Prednisone, but not sure the other ones they were giving to treat him. He was still on Prednisone. She did not have a lot or expiration as it is in a pharmacy vial. She does not have lot or expiration for ones given in the hospital. He was hospitalized from Apr2021 to Aug2021 and had a short period of time that he had to go back to the hospital because of seizures again. They were not sure why he was still having seizures since he was on the medication, Depakote and Keppra. The doses had been changed. First, he was taking 500mg Depakote twice daily and thought when he checked blood work, his numbers were high, and they had to come down. Then she corrected and said he was still on that. It was the Keppra that was changed. Keppra was 1500 mg twice daily, but when they did blood work 2 weeks ago, his numbers were high, and they cut him to 1,000 mg twice daily. The patient underwent lab tests and procedures which included antibody test: positive and blood test: negative on an unspecified date in 2021. Therapeutic measures were taken as a result of lost his ability to think, walk and talk, autoimmune encephalitis. Patient was still having seizures despite being on medication for it. He was on Depakote and Keppra. The doses have been changed. First, he was taking 500mg Depakote twice daily and thought when he checked blood work, his numbers were high, and they had to come down. No lot or expiration, as it was in a pharmacy vial. Then she corrected and said he was still on that. It was the Keppra that was changed. Keppra was 1500 mg twice daily, but when they did blood work 2 weeks ago, his numbers were high, and they cut him to 1,000 mg twice daily. It was in a pharmacy vial with no lot or expiration. Product strength and count size dispensed: Keppra 1500 mg, unknown count. Depakote 500mg, unknown count. The outcome of the event autoimmune encephalitis was recovered with sequelae, of lost his ability to think, walk and talk and seizure was recovering and that of swelling of brain and tired was unknown.  No follow-up attempts are needed. No further information is expected.