acute pericarditis; Fever; chest pain; muscle weakness; somnolence; This is a spontaneous report received from a contactable reporter(s) (Physician). The reporter is the patient.  A 60-year-old female patient (not pregnant) received BNT162b2 (BNT162B2), on 06Feb2022 at 15:45 as dose 3 (booster), single (Lot number: FK9895) at the age of 61 years intramuscular, in left arm for covid-19 immunisation. The patient's relevant medical history included: "Migraine" (unspecified if ongoing); "headache" (unspecified if ongoing); "Hypertension intermittent" (unspecified if ongoing). The patient's concomitant medications were not reported. Vaccination history included: BNT162b2 (Dose Number: 2, Batch/Lot No: EN6198, Location of injection: Arm Left, Vaccine Administration Time: 03:45 PM, Route of Administration: Intramuscular), administration date: 24Feb2021, when the patient was 60-year-old, for COVID-19 Immunization, reaction(s): "difficulties to focus", "Giulian-Barre syndrome with fever", "Giulian-Barre syndrome with fever", "Severe muscle weakness", "Somnolence"; BNT162b2 (Dose Number: 1, Batch/Lot No: EN5318, Location of injection: Arm Left, Vaccine Administration Time: 01:30 PM, Route of Administration: Intramuscular), administration date: 04Feb2021, when the patient was 60-year-old, for COVID-19 Immunization, reaction(s): "difficulties to focus", "Giulian-Barre syndrome with fever", "Giulian-Barre syndrome with fever", "Severe muscle weakness", "Somnolence". The following information was reported: PYREXIA (non-serious) with onset 2022, outcome "recovered with sequelae", described as "Fever"; PERICARDITIS (medically significant) with onset 2022, outcome "recovered with sequelae", described as "acute pericarditis"; CHEST PAIN (non-serious) with onset 2022, outcome "recovered with sequelae"; MUSCULAR WEAKNESS (non-serious) with onset 2022, outcome "recovered with sequelae", described as "muscle weakness"; SOMNOLENCE (non-serious) with onset 2022, outcome "recovered with sequelae". The patient underwent the following laboratory tests and procedures: SARS-CoV-2 test: (13Dec2020) Negative, notes: Nasal Swab; (13Jan2022) Negative, notes: Nasal Swab; (07Mar2022) Negative, notes: Nasal Swab; (27Apr2022) Negative, notes: Nasal Swab. Therapeutic measures were taken as a result of pericarditis, pyrexia, chest pain, muscular weakness, somnolence. For the treatment the patient took bed rest, Valacyclovir 1000 mg PO QID, Ibuprofen 400 mg PO TID. The patient did not receive any other vaccine in four weeks. The patient did not receive any other medication in two weeks. The did not have covid Prior vaccination. The patient was not tested with covid post vaccination. The patient had acute pericarditis with fewer, chest pain, muscle weakness, somnolence after 3rd (booster) vaccination. It was reported that that recovery was incomplete as of 20Jun2022 with muscle weakness and difficulties to focus and complete tasks. The patient was reported as recovered with lasting effects.; Sender's Comments: Based on known drug safety profile, the event acute pericarditis assessed as related to the suspect product BNT162b2. The case will be reassessed once further information is available The impact of this report on the benefit/risk profile of the Pfizer product is evaluated as part of Pfizer procedures for safety evaluation, including the review and analysis of aggregate data for adverse events. Any safety concern identified as part of this review, as well as any appropriate action in response, will be promptly notified to RAs, Ethics Committees, and Investigators, as appropriate.