It was a positive adverse event, not a negative/adverse issue.  I have had chronic fatigue syndrome for years, with no known genesis, with many of the same symptoms that people are now experiencing.; Administration date: 08Nov2021; Dose number: 3; Administration date: 08Nov2021; Dose number: 3; Administration date: 08Nov2021; Dose number: 3; This is a spontaneous report from a contactable consumer (patient).  A 44-year-old non-pregnant female patient received bnt162b2 (PFIZER-BIONTECH COVID-19 mRNA VACCINE, Solution for injection, Batch/Lot number was not reported), via an unspecified route of administration, administered in left arm on 08Nov2021 16:30 (at the age of 44-year-old) as DOSE 3 (BOOSTER), SINGLE for COVID-19 immunization. Facility type vaccine: Doctor's office/urgent care. Medical history included chronic fatigue syndrome, depression/anxiety, wolff parkinson white (but treated with ablation many years ago), brain fog (she felt her brain fog lift. She literally cannot remember the last time she didn't have brain fog) and patient had known allergies to codeine -all from an unknown date and unknown if ongoing. No other vaccine administered in four weeks. Patient did not had covid prior vaccination and did not tested post vaccination. The patient was not pregnant at the time of vaccination. Concomitant medications, within two weeks included venlafaxine hydrochloride (EFFEXOR) and bupropion hydrochloride (WELLBUTRIN), both taken for an unspecified indication, start and stop date were not reported. The patient previously took codeine and experienced allergy. The patient had previously received first dose of MODERNA COVID-19 VACCINE (Batch/ Lot Number: Unknown) (reported as Not available/provided to reporter at the time of report completion) via an unspecified route of administration, administered in left arm on 14Jan2021,15:00 (at the age of 43-years-old), as dose 1, single and second dose of MODERNA COVID-19 VACCINE (Batch/ Lot Number: Unknown) (reported as Not available/provided to reporter at the time of report completion) via an unspecified route of administration, administered in left arm on 11Feb2021, 11:00 (at the age of 43-years-old), as DOSE 2, SINGLE, both doses for COVID-19 immunization. The patient had administration date: 08Nov2021; dose number: 3. On 09Nov2021, 05:00, the patient experienced it was a positive adverse event, not a negative/adverse issue.  I have had chronic fatigue syndrome for years, with no known genesis, with many of the same symptoms that people are now experiencing. It was reported that about adverse event, It was a positive adverse event, not a negative/adverse issue. I have had chronic fatigue syndrome for years, with no known genesis, with many of the same symptoms that people are now experiencing with long covid-oppressive fatigue, brain fog, dizziness upon standing, poor circulation in hands/feet, and extreme fatigue after exercise. About 12 hours after I received my Pfizer booster shot, I felt my brain fog lift. I literally cannot remember the last time I didn't have brain fog. To be fair, It was only been a few days, and I am extremely hopeful that this state continues, but it was an amazing change. I feel like a different person. No idea if related but seemed like it would be too great a coincidence if not related. No treatment received for the event. Outcome of the event were unknown.  The lot number for the vaccine, [BNT162B2], was not provided and will be requested during follow up.