doesn't have as good concentration as he used to have/concentration problem; a little forgetful about things/he noticed the forgetfulness; This is a spontaneous report from a contactable consumer. This 65-year-old male consumer (Patient) reported that: The reporter is the patient. A 65 year-old male patient received bnt162b2 (BNT162B2), administration date 12Mar2021 (Lot number: EN6205) at the age of 65 years as dose 2, single for covid-19 immunisation. Relevant medical history included: "Stroke" (unspecified if ongoing), notes: he had a stroke about 4 years ago, maybe in 2017, he's not really sure.; "Stents in his heart" (unspecified if ongoing); "spot on his liver" (unspecified if ongoing), notes: The spot on his liver is not cancer it's a mineral deposit or something. He had a biopsy and it was negative.; "polycystic kidney disease" (unspecified if ongoing); "mineral deposit" (unspecified if ongoing), notes: The spot on his liver is not cancer it's a mineral deposit or something. Concomitant medication(s) included: METFORMIN taken for congenital cystic kidney disease. Vaccination history included: Bnt162b2 (Dose:1 Batch/lot number: EN6205, ), administration date: 19Feb2021, when the patient was 65 years old, for covid-19 immunization, reaction(s): "dose was 0.2 mg". The following information was reported: DISTURBANCE IN ATTENTION (non-serious) with onset 2021, outcome "not recovered", described as "doesn't have as good concentration as he used to have/concentration problem"; MEMORY IMPAIRMENT (non-serious) with onset 2021, outcome "not recovered", described as "a little forgetful about things/he noticed the forgetfulness". Relevant laboratory tests and procedures are available in the appropriate section.  Additional information: He's calling about the booster dose for the Covid 19 vaccine. He received the first 2 doses, he is asking if there's a way for him to be contacted when he's eligible for the Covid 19 booster. When probing if caller is reporting an adverse event he reports he noticed he doesn't have as good concentration as he used to have after receiving the Pfizer Covid 19 vaccine. He reports it's not terrible and he is getting older, he had a birthday yesterday and he has had a stroke. He's a little forgetful about things, his long term memory is good and he doesn't know if his memory is related to his stroke or if it's an adverse reaction from the vaccine or his old age. He reports he used to work in a hospital and institution in the food industry. When probing for information regarding the dates that he received the Covid 19 vaccine he reports he received the second dose exactly 2 weeks after the first dose. After further probing it is determined based on the dates the caller sees on his Covid 19 vaccine record card, he received the second dose 3 weeks after the first dose, not 2 weeks. He received the first dose on 19Feb2021 and the second dose on 12Mar2021. When probing for the lot number of the first dose received on 19Feb2021, he reports it's blurred. It's a sticker in the middle of the card by the date of the first vaccine dose, he will try using a magnifying glass to see the numbers and letters. He reports it's very blurred, not a very clear print. He can not see the lot number for the first dose and he reports he sees 0.2 mg. Verified with caller that he sees 0.2 mg.. The spot on his liver is not cancer it's a mineral deposit or something. He had a biopsy and it was negative. He gets blood tests all the time to make sure everything is still functioning like it should. He's being monitored. He has no problem except the forgetfulness. He has not had to see a doctor or had any tests done related to his side effects with the Covid 19 vaccine. He states he takes Metformin and he doesn't know if that has anything to do with it. He knows Metformin is a bad drug and the doctor doesn't like prescribing it but that's what he takes to help control his diabetes. He doesn't have diabetes, the doctor is prescribing it as a precaution so he doesn't get diabetes because of his polycystic kidney disease. He knows it's a bad drug and he doesn't know who makes it but he's been taking it for 30 years probably. He would like to stop taking the Metformin but he doesn't know if that's a good idea or not.  Follow-up attempts are completed. No further information is expected.