adds loss of appetite; Began violently shaking, her full body and felt cold; Began violently shaking, her full body and felt cold; Felt not overwhelming nausea; felt she should not be eating.; Slept for 24 hours/sleepy; Lost weight/lost 6 pounds recently; Tired; sleepy; This is a spontaneous report received from contactable reporter (Nurse). The reporter is the patient.  An 87-year-old female patient received BNT162b2, BNT162b2 omi ba.4-5 (BNT162B2, BNT162B2 OMI BA.4-5), on 27Oct2022 as dose 5 (booster), single (Lot number: GJ6665) at the age of 87 years for prophylaxis. The patient's relevant medical history was not reported. Concomitant medication(s) included: FLU VACCINE VII, in Oct2022 as dose number unknown, single. Vaccination history included: BNT162b2 (Dose 1, Anatomical Site of injection: left arm, Route of Administration: intramuscular, Batch/Lot number: EL9262), administration date: 24Jan2021, when the patient was 85-year-old, for COVID-19 immunization; BNT162b2 (Dose 2, Anatomical Site of injection: left arm, Route of Administration: intramuscular, Batch/Lot number: EL9266), administration date: 14Feb2021, when the patient was 85-year-old, for COVID-19 immunization; BNT162b2 (Dose 3, Anatomical Site of injection: left arm, Route of Administration: intramuscular, Batch/Lot number: FF8839), administration date: 02Nov2021, when the patient was 86-year-old, for COVID-19 immunization; BNT162b2 (Dose 4, Anatomical Site of injection: left arm, Route of Administration: intramuscular, Batch/Lot number: FK9893), administration date: 27Apr2022, when the patient was 86-year-old, for COVID-19 immunization, reaction(s): "lost 20 pounds prior to the bivalent booster.". The following information was reported: TREMOR (medically significant), FEELING COLD (medically significant) all with onset 27Oct2022, outcome "recovered" (28Oct2022) and all described as "Began violently shaking, her full body and felt cold"; NAUSEA (medically significant) with onset 27Oct2022, outcome "recovered" (30Oct2022), described as "Felt not overwhelming nausea; felt she should not be eating."; WEIGHT DECREASED (medically significant) with onset 27Oct2022, outcome "recovered" (30Oct2022), described as "Lost weight/lost 6 pounds recently"; SOMNOLENCE (medically significant) with onset 27Oct2022, outcome "recovered with sequelae" (28Oct2022), described as "Slept for 24 hours/sleepy"; FATIGUE (medically significant) with onset 27Oct2022, outcome "recovering", described as "Tired; sleepy"; DECREASED APPETITE (medically significant), outcome "recovering", described as "adds loss of appetite". Clinical course details: 8 hours after getting the vaccine she began violently shaking, her full body and felt cold. Felt not overwhelming nausea; felt she should not be eating. Stayed in bed and slept for 24 hours, except for the bathroom breaks. States she lost lost 6 pounds recently and lost 20 pounds prior to the bivalent booster. It was reported that, the patient had not had any reactions before that.; Sender's Comments: Considering the plausible drug-event temporal association, there is a reasonable possibility that reported events were related to BNT162B2 vaccine administration. Case will be reassessed upon receipt of additional information. 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 Regulatory Authorities, Ethics committees and Investigators, as appropriate.