Chills; Body aches; Joint pain; 101.9 fever; Extreme tiredness; Hyperimmune or autoimmune response; This is a spontaneous report received from a contactable reporter(s) (Consumer or other non HCP) in response to consumer letter sent via follow-up letter. The reporter is the patient. A 69-year-old female patient received bnt162b2 (BNT162B2), intramuscular, administered in arm left, administration date 08Feb2021 08:30 (Lot number: EL9264) at the age of 69 years as dose 2, single for covid-19 immunisation. Relevant medical history included: "High blood pressure" (unspecified if ongoing). Concomitant medication(s) included: VALSARTAN HCT taken for hypertension (ongoing); TYLENOL taken for pyrexia, pain, start date: 08Feb2021, stop date: 19Oct2021. Vaccination history included: Bnt162b2 (Dose 1, Single, Anatomical site of administration: Left arm, Route of administration: Intramuscular, Administration time: 8:30 AM, Lot number: EL3247), administration date: 18Jan2021, for COVID-19 immunisation, reaction(s): "Sore arm". The following information was reported: CHILLS (non-serious) with onset 08Feb2021 22:00, outcome "recovered" (12Feb2021), described as "Chills"; PAIN (non-serious) with onset 08Feb2021 22:00, outcome "recovered" (12Feb2021), described as "Body aches"; ARTHRALGIA (non-serious) with onset 08Feb2021 22:00, outcome "recovered" (12Feb2021), described as "Joint pain"; PYREXIA (non-serious) with onset 08Feb2021 22:00, outcome "recovered" (Feb2021), described as "101.9 fever"; FATIGUE (non-serious) with onset 08Feb2021 22:00, outcome "unknown", described as "Extreme tiredness"; IMMUNE SYSTEM DISORDER (non-serious) with onset 2021, outcome "unknown", described as "Hyperimmune or autoimmune response". Relevant laboratory tests and procedures are available in the appropriate section. Therapeutic measures were taken as a result of pain, arthralgia, pyrexia.  Additional information: By 10 pm, she began experiencing chills, body aches, joint pain and 101.9 fever. This lasted for 4 days followed by 100-degree fever for another day and extreme tiredness for several weeks. In light of this reaction, she was hesitant to obtain a booster shot without discussing this with a professional medical adviser. Her concern was that this was not a typical response and that she was experiencing a hyperimmune or autoimmune response. Also, Guillain-Barre syndrome crossed her mind. At that time, she did not consider that the product was defective, but rather that something in her immune system might be amiss. On 27Sep2021, while at a well-care visit, she discussed this reaction with her physician. She recommended that perhaps she could delay taking the booster if she checked her antibody titters. She was not comfortable with putting off the inevitable, taking a booster, since she was over 65 years old. The following day, she called facility to obtain reassurance that her reaction was normal, and it would be safe to make an appointment for a booster shot. She spoke to the medical division. She advised to speak to her physician which she had already done and she read off a list of common reactions. She did not experience a rash, hives, low grade fever, or any other anaphylaxis event. With no clear direction on whether or not the booster would be safe for her to take, she made the decision to take a booster on 15Oct2021 at 1 pm. By 10 pm that night she once again had severe tremors, chills, aches, joint pain and 101.7 fever which lasted for three days followed by extreme fatigue. She was currently relieved that she was as protected as possible from Covid-19 but concerned that she will have to obtain a yearly booster shot for the disease. Perhaps it was not safe for her to do so? Is her reaction abnormal? If you wish to contact her, she can be reached. Booster dose due to high risk of frequent institutional or occupational exposure to coronavirus (and at risk of serious covid-19 complications). Vaccination was not administered at military facility. Prior vaccination (within 4 weeks) was none. Relevant tests were none. Specific relevant test for thromboembolic events with thrombocytopenia was none.  Follow-up attempts are completed. No further information is expected.; Sender's Comments: Linked Report(s) : US-PFIZER_INC-202101546712 same drug and patient, different event and drug dose;US-PFIZER INC-202101281664 same drug and patient, different event and drug dose