Really bad chronic fatigue syndrome; but events worsened after the 3rd dose was administered; Severe headaches, chronic, they never go away; This is a spontaneous report received from a contactable reporter(s) (Nurse). The reporter is the patient.  An 82-year-old female patient received BNT162b2 (BNT162B2), on 12Oct2021 as dose 3 (booster), single (Batch/Lot number: unknown) at the age of 82 years, in right arm for covid-19 immunisation. The patient's relevant medical history included: "Dust allergy" (unspecified if ongoing); "Fibromyalgia" (unspecified if ongoing); "arthritis" (unspecified if ongoing); "breast cancer" (ongoing). There were no concomitant medications. Vaccination history included: BNT162b2 (Dose 1), administration date: 24Jan2021, when the patient was 82-year-old, for COVID-19 immunization, reaction(s): "Severe headaches, chronic, they never go away"; BNT162b2 (Dose 1), administration date: 24Jan2021, when the patient was 82-year-old, for Covid-19 Immunization, reaction(s): "Really bad chronic fatigue syndrome"; BNT162b2 (Dose 2, Severe headaches, chronic, they never go away), administration date: 14Feb2021, when the patient was 82-year-old, for Covid-19 Immunization, reaction(s): "Severe headaches, chronic, they never go away"; BNT162b2 (Dose 2, Really bad chronic fatigue syndrome), administration date: 14Feb2021, when the patient was 82-year-old, for COVID-19 immunization, reaction(s): "Really bad chronic fatigue syndrome". The following information was reported: CHRONIC FATIGUE SYNDROME (disability), outcome "not recovered", described as "Really bad chronic fatigue syndrome"; CONDITION AGGRAVATED (disability), outcome "not recovered", described as "but events worsened after the 3rd dose was administered"; HEADACHE (disability), outcome "not recovered", described as "Severe headaches, chronic, they never go away". The patient underwent the following laboratory tests and procedures: Echocardiogram: (Aug2021) Did not show anything, notes: Result: Did not show anything; Unit: Not Provided; Weight: (unspecified date) She should lose a little bit of weight, notes: She should lose a little bit of weight, but that is impossible because the treatment for the breast cancer prevents her from ever losing any weight. Clinical course: This reporter initially reported on behalf of herself who called regarding Pfizer product: Covid Pfizer CV. Later in the report she mentioned that she was a retired nurse who was also the patient. The first dose was administered on 24Jan2021 (Lot: EK0231, expiry date 30Apr2021) dose 0.3mL injection to right arm. She believed the third character was a zero, but it was hard to say as it was so small on CDC vaccine record card. NDC: Unknown, not on CDC Vaccine record card. The second dose was administered on 14Feb2021 (Lot: EL0264, expiry date 31May2021), dose: 0.3mL injection to right arm. She believed that was correct from CDC vaccine record card. She has had side effects since 15Feb2021. Third dose was administered: 12Oct2021 (Lot: hard to read, handwritten on CDC vaccine record card, thought it was FF2590, but it could be FF2570). No additional vaccines were administered on the same date of the Pfizer Suspect, the patient did not receive any other vaccines within four weeks prior to the vaccination. Relevant medical history included she could go into diabetes if she neglected what she ate but she controlled everything with diet and exercise. She should lose a little bit of weight, but that was impossible because the treatment for the breast cancer prevented her from ever losing any weight. From Jul2020 to Dec2020 she went back to help out with a family crisis and when she was there, her family verified that she was functioning at top capacity from 8am until 10pm with no complaint of headache or fatigue. She didn't have the flu or anything like that. She had recurrent breast cancer and was ongoing follow up for 3rd bout of breast cancer, recurrent breast cancer. There was no relevant family medical history. She has had side effects since 15Feb2021. Adverse Event included severe headaches, chronic, they never go away. She was having a tough time. She can't continue to live with these side effects and did not know what to be done. She had been seeing doctors about these side effects and they don't know what to do. She clarified the side effects as being severe headaches, chronic, they never went away and really bad chronic fatigue syndrome. She was not foolish enough to think that she was the only one who had gotten those injections and had those side effects. She did not know if Pfizer was even interested in keeping track of this kind of side effect to try to do something about it in the future. These events had left her capable of doing nothing, it had taken away her life. Initially events were persistent, but events worsened after the 3rd dose was administered 12Oct2021. She was down on the bed like 24/7 and only got up for the bathroom and got up to quickly fix something to eat that's all she can do. The fatigue was so bad, at times the headaches kept her flat for 2 solid days. She's always been superwoman and this had ruined her life. The AE(s) did not require a visit to emergency room or physician office but she had just infrequently gone to the doctor to see if there has been any change.  The information on the batch/lot number for BNT162b2 has been requested and will be submitted if and when received.; Sender's Comments: As there is limited information in the case provided, the causal association between the reported events: "Chronic fatigue syndrome", "Condition worsened", "Headache" and the suspect drug BNT162B2 cannot be excluded. The case will be reassessed once new information is available.   The impact of this report on the benefit/risk profile of the Pfizer drug 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.