was advised that if the fever reached 104 to go to the ER and that the chills and rare high fever could be due to having Hashimoto Thyroiditis; At 18hrs after 2nd shot, sore arm with headache and fever around 101.; At 18hrs after 2nd shot, sore arm with headache and fever around 101.; At 18hrs after 2nd shot, sore arm with headache and fever around 101.; Around 24hrs after, chills were off and on throughout the day; I felt dizzy; At 30hrs after, uncontrollable shivering/shaking for about 15 minutes; unstable, raised heartrate and had brain fog; unstable, raised heartrate and had brain fog; This is a spontaneous report from a non-contactable consumer (patient). A 39-years-old female non pregnant patient received bnt162b2 (PFIZER-BIONTECH COVID-19 VACCINE, Solution for injection, Batch/Lot Number: EW0191) via an unspecified route of administration in Arm Left on 30Jul2021 at 15:00 (at the age of  39-years-old) as dose 2, single for COVID-19 immunisation. The patient was not pregnant at the time of vaccination.  The medical history included hashimoto disease, Subclinical Hypothyroidism, Low Ferritin and Iron, Vitamin D and B deficient, allergies, Known allergies to dairy/Milk, Outdoor allergens (Trees, Grass, Dust) and dogs from an unknown date and unknown if ongoing. The concomitant medications included (other medications taken in two weeks) ferrous gluconate (FERROUS GLUCONATE) taken for an unspecified indication, start and stop date were not reported; cyanocobalamin (VITAMIN B12 [CYANOCOBALAMIN]) taken for an unspecified indication, start and stop date were not reported; vitamin d3 (VITAMIN D3) taken for an unspecified indication, start and stop date were not reported. The patient previously took amoxicillin and experienced drug hypersensitivity and bnt162b2 (PFIZER-BIONTECH COVID-19 VACCINE, Solution for injection, Batch/Lot Number: EW0187) via an unspecified route of administration in Arm Left on 08Jul2021 at 03:30 PM (at the age of 39-years-old) as dose 1, single for COVID-19 immunisation. The patient had no COVID prior vaccination, was not COVID tested post vaccination, did not take other vaccine in four weeks. The patient stated that at 18hrs after 2nd shot, she experienced sore arm with headache and fever (31Jul2021) around 101. Around 24hrs after, chills (31Jul2021) were off and on throughout the day, constant headache, dizzy and fever (31Jul2021) around 101-102. At 30hrs after, had uncontrollable shivering/shaking (31Jul2021) for about 15 minutes and fever spiked to 103.8, felt dizzy, unstable, raised heartrate (31Jul2021) and had brain fog (31Jul2021). Fever of 102-103.8 remained for about 2 hours. The next two days, fever stayed between 101-102 and she felt dizzy to be at work or to stand, she called a consulting nurse and was advised that if the fever reached 104 to go to the ER and that the chills and rare high fever could be due to having Hashimoto Thyroiditis (31Jul2021). No treatment was taken for events except fever and sore arm; After taking 500mg acetaminophen and a cool shower, fever lowered to around 102. The patient underwent lab test and procedure which included fever: 102 Fahrenheit, fever: 101-102 Fahrenheit, fever: 103.8 Fahrenheit, fever: 102-103.8 Fahrenheit, fever: around 101Fahrenheit all on 31Jul2021. The patient stated that after 4 full days, she was feeling normal again. The outcome of event I felt dizzy was recovered on an unspecified date in 2021 while rest of events were recovered on 04Aug2021.    No follow up attempts were possible. No further information was expected.