Pericarditis; This is a spontaneous report received from contactable reporter(s) (Consumer or other non HCP) from medical information team. The reporter is the patient.  A 65-year-old female patient received BNT162b2 (BNT162B2), on 12Dec2021 as dose 3 (booster), single (Lot number: FD7218) at the age of 65 years, in right arm for covid-19 immunisation. The patient's relevant medical history included: "Hypothyroidism" (unspecified if ongoing); "Parathyroid", start date: 2019 (unspecified if ongoing), notes: Treated for parathyroid in 2019. Removed 2 parathyroid glands. That was before COVID. Concomitant medication(s) included: LEVOTHYROXINE taken for hypothyroidism. Vaccination history included: BNT162b2 (Dose 1, single; Lot: EW0158 expiration: Unknown, anatomical location: Injected in right arm), administration date: 20Apr2021, when the patient was 65-year-old, for Covid-19 immunization; BNT162b2 (Dose 1, single; Lot: EW0158 expiration: unknown, anatomical location: Injected in right arm), administration date: 21May2021, when the patient was 65-year-old, for Covid-19 immunization. The following information was reported: PERICARDITIS (medically significant) with onset Feb2022, outcome "not recovered". Therapeutic measures were taken as a result of pericarditis. Caller stated that she received her first booster shot of the Pfizer-BioNTech Covid 19 Vaccine on 12Dec2021 and after that she has been suffered with pericarditis and she still has it. She wants to know if this side effect has been reported due to the vaccine because she can't get rid of it. Caller stated that it is a disgrace that Pfizer does not have information on how to treat pericarditis due to the vaccine. She also mentioned that this side effect should be a headline and Pfizer must disclose it, also saying that "this is bad and not good". Caller wanted to verify if this call is being recorded, so she can have evidence that she spoke to us. Additional information on drug: Additional Information for Other medicines Levothyroxine: Taking 20 years. Dosage and Relevant Information: Dosage text: Unknown Dose. 0.75 mcg. once daily. Case narrative including clinical course, therapeutic measures, outcome, and additional relevant information: Dates when patient was in hospital for Heart Operation: 27Jan2022 to 30Jan2022. Warm transfer from (name withheld), Pfizer Global Switchboard. She has a lady who had reaction to Pfizer COVID booster. Patient confirmed information above. She would like to know if we have any data that this is happening to people that they are getting Pericarditis from the booster. She does not know if it came from the booster. She first started providing address, then changed to the address where she is currently. She also had an operation. She took the booster when she was 65. Her aunt was reading things and said she thinks the reason she is not getting rid of it is because of the booster. They kept her on steroids for 30 days. She gets off and gets sick again in 3 days and then is on for another 30 days. Unknown lot and expiration and names of the steroids. She just knows the dosage and was prescribed through #. When she was on it, it was good, but when off, it came back. She does not know where inflammation is coming from. She will see a specialist. It gets worse when it is not being treated with medication. When she was diagnosed with it, the only medication she was taking prior was Levothyroxine. She takes supplements. Treated for parathyroid in 2019. Removed 2 parathyroid glands. That was before COVID. Description of Product Complaint: Description of complaint: They kept her on steroids for 30 days. She gets off and gets sick again in 3 days and then is on for another 30 days. Unknown lot and expiration and names of the steroids. She just knows the dosage and was prescribed through. When she was on it, it was good, but when off, it came back. Product strength and count size dispensed: not provided.  No follow up attempts are possible. No further information is expected.