pain in her legs all around from her pelvic bone to her legs, thighs, calves, and shins, in both legs; does feel like a nerve pain; deep pain, pain in her bones; prevents her from falling asleep and wakes her up in the middle of the night; prevents her from falling asleep and wakes her up in the middle of the night; bone marrow reconversion; This is a spontaneous report from a contactable nurse (patient). A 42-year-old female patient received bnt162b2 (PFIZER-BIONTECH COVID-19 VACCINE), dose 1 intramuscular on 02Feb2021 19:30 (Batch/Lot Number: EM9810) (at the age of 42 years) as DOSE 1, SINGLE for covid-19 immunisation. Medical history included non-tobacco user from an unknown date and unknown if ongoing. The patient's concomitant medications was none. The patient experienced pain in her legs all around from her pelvic bone to her legs, thighs, calves, and shins, in both legs, nerve pain, deep pain, pain in her bones, prevents her from falling asleep and wakes her up in the middle of the night, bone marrow reconversion (all with criteria of disability) on Feb2021 with outcome of not recovered. She got her first dose on 02Feb2021. After 12 days she started having pain in her legs all around from her pelvic bone to her legs, thighs, calves, and shins, in both legs. She called a neurologist and was told it was ok to get the second dose. The neurologist said it will probably go away. It had been close to 6 months and she was still having the pain. She has had a lot of testing done and saw specialists. They saw something on her MRI of the leg that could not be explained. She had a bone marrow biopsy that was negative. The pain in both legs was staying the same. She has some better days or weeks but then the pain comes back very unexpected in the areas of her legs that she mentioned above. Sometimes it was a pain that comes and goes. Sometimes it does feel like a nerve pain and the severity of the pain when it feels like a nerve pain is a 5 out of 10. It was disabling, since she cannot do things she used to do before. She also had other types of pain like deep pain, pain in her bones which caused an MRI to be ordered. The pain has stayed for hours and prevents her from falling asleep and wakes her up in the middle of the night. It was very random when the pain happens and she cannot fall back asleep. The pain can happen anywhere or anytime. She cannot get comfortable. It does not happen every night. The symptoms she was experiencing are very odd for her to be feeling since before the shots she was running, doing yoga, and dancing a few times a week. She has been very active/athletic her whole life. Causality was unknown, the doctors were not finding a different reason and the timing. She saw a hematologist-oncologist, and she was told that she was his third patient in the last one or two months with similar MRI findings. She clarified her MRI findings as: Impression: bone marrow reconversion. She had tons of blood work done. All of her blood work and nerve conduction test came back normal. She also saw a rheumatologist that ruled out any autoimmune disease. The patient underwent lab tests and procedures which included biopsy bone marrow: negative, blood test: normal, magnetic resonance imaging: impression: bone marrow reconversion, nerve conduction studies: normal, pain assessment: 5 out of 10; all on Feb2021. Therapeutic measures were taken as a result of events. She started taking gabapentin. She tried Cymbalta first and that was really bad, so she switched to Gabapentin.; Sender's Comments: Based on the information available , a possible contributory role of the suspect BNT162B2 cannot be excluded for the reported events . The case will be reassessed once new information is available. The impact of this report on the benefit/risk profile of the Pfizer product 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