experienced extreme pain for 12 days following the injection, in her entire arm/ pain continued to spread down her arm and to her hand; experienced extreme pain for 12 days following the injection, in her entire arm, shoulder, neck, up to her left ear, and sharp shooting pains throughout her back; experienced extreme pain for 12 days following the injection, in her entire arm, shoulder, neck, up to her left ear, and sharp shooting pains throughout her back; experienced extreme pain for 12 days following the injection, in her entire arm, shoulder, neck, up to her left ear, and sharp shooting pains throughout her back; experienced extreme pain for 12 days following the injection, in her entire arm, shoulder, neck, up to her left ear, and sharp shooting pains throughout her back; dose 1 subcutaneously, administered in left arm; discomfort; could not move her neck or arm due to pain; could not move her neck or arm due to pain; The initial case was missing the following minimum criteria: no adverse event. Upon receipt of follow-up information on 15Mar2021, this case now contains all required information to be considered valid.  This is a spontaneous report from contactable consumers (one of them was patient). A 34-year-old female patient received BNT162B2 (PFIZER-BIONTECH COVID-19 mRNA VACCINE, solution for injection, Batch/Lot Number: EC3302), dose 1 subcutaneously, administered in left arm on 22Jan2021 08:09 (at the age of 34-year-old) at 0.3 ml as single dose for COVID-19 immunization. Medical history included MTHFR C677T/A1298C mutations from Mar2018 and ongoing (onset date unknown, was diagnosed after positive lab results in Mar2018). The patient's concomitant medications were not reported. Additional vaccines administered on same date of the Pfizer Suspect, Prior Vaccinations (within 4 weeks) and AE(s) following prior vaccinations were reported as not applicable. Patient stated, first dose injection was administered subcutaneously (22Jan2021 08:09) on left arm; experienced extreme pain for 12 days following the injection, in the entire arm, shoulder, neck, up to left ear, and sharp shooting pains throughout her back (starting around 14:00 on the day of the injection). The patient went to the ER (emergency room) 3 days post injection and was told to take ibuprofen until the pain subsided. Ibuprofen did not relieve any pain. Patient again stated, on 25Jan2021, went to the ER because the pain continued to spread down her arm and to her hand. She could not move her neck or arm due to pain. The ER doctor confirmed the injection site was subcutaneous and that was causing an unexpected reaction. The patient was told to take ibuprofen around the clock until the pain goes away so she tried for about 36 hours, but there was no relief. She experienced the extreme pain and discomfort for 12 days, until 03Feb2021 a week (and 2 days) prior to her second dose. Patient was not hospitalized. No other product(s) were not taken together. Patient visited Emergency Room and not visited Physician Office (communicated with Primary Care Physician over email, following ER visit). The patient would like to have an antibody test, so queried to advise how she can arrange that, and also reported that she donated blood, but their antibody tests for a different type of antibodies from actually having covid, not from getting the vaccine so her results were negative. Hopefully can arrange for the correct type of antibody test. The outcome of events 'experienced extreme pain for 12 days following the injection, in her entire arm, shoulder, neck, up to her left ear, and sharp shooting pains throughout her back', 'experienced extreme pain for 12 days following the injection, in her entire arm/ pain continued to spread down her arm and to her hand', 'could not move her neck or arm due to pain' and discomfort was reported as resolved on 03Feb2021.  No follow-up attempts are needed. No further information is expected  Amendment (16Jun2021): This follow-up report is being submitted to amend previously reported Information: removed the classification of at risk from the general tab.