Swelling around her spine; Could not stand up; Hinge back pain; This is a spontaneous report received from a contactable reporter(s) (Consumer or other non HCP) from medical information team. The reporter is the patient. A 64-year-old female patient received BNT162b2 (BNT162B2), on 09Apr2022 at 11:00 as dose 4 (booster), single (Lot number: FK9893) at the age of 64 years, in left arm for covid-19 immunisation; alendronate sodium (FOSAMAX), (Batch/Lot number: unknown). The patient's relevant medical history included: "Osteoporosis" (unspecified if ongoing); "Celiac disease" (unspecified if ongoing). Concomitant medication(s) included: CALCIUM taken for osteoporosis; PROLIA taken for osteoporosis. No prior vaccinations (within 4 weeks). Vaccination history included: BNT162b2 (Dose 1, Single), administration date: 25Feb2021, when the patient was 63-year-old, for Covid-19 Immunisation; BNT162b2 (Dose 2, Single), administration date: 26Mar2021, when the patient was 63-year-old, for Covid-19 Immunisation; BNT162b2 (Dose 3 (BOOSTER), Single), administration date: 26Sep2021, when the patient was 64-year-old, for COVID-19 Immunisation. The following information was reported: BACK PAIN (medically significant) with onset 09Apr2022 at 22:00, outcome "unknown", described as "Hinge back pain"; SWELLING (non-serious), outcome "unknown", described as "Swelling around her spine"; DYSSTASIA (non-serious), outcome "unknown", described as "Could not stand up". She was calling to report a serious and rare adverse effect that she had to her second booster, her fourth vaccine. She went to the doctor yesterday, got her fourth vaccine which was her second booster on Saturday, this past Saturday and by Sunday, she had a Hinge back pain but not as bad, she thought she could go to work. Yesterday, she woke up and she could not stand up, she could not stand up, Sunday night for, upright, make herself upright with that excruciating pain. It was so intense that she had never felt anything like it in her life and she could not bear it. So, she called her doctor, she went in, told him everything. She did not tell him about the vaccine because she had no idea that could be it. She did not even think about it. She just found out that there has been few other that was very rare, transverse Myelitis Cases. She has been researching it for 2 days. There are very few cases of it. When paraphrased the concern, consumer stated, yes, she went to the doctor and he, she was going to go get an X-ray today, probably have to get an MRI, but he gave her, she did not tell him about the vaccine. She did not know it could be related. She just did not know what was going on because she does have osteoporosis, but it was very early stage and she do take Prolia, which was known (incomplete sentence) and she take Calcium, so he said no it was not because of that. When clarified the adverse event, consumer stated, He (doctor) believes that she has swelling around her spine, and he gave her steroid shot yesterday and he gave her a prescription for what it was called Prednisone (later clarified as Methylprednisolone) which starts today, and doctor gave her a prescription for Tizanidine, and he gave her the Methylprednisolone 4mg for 5 days (Treatment for adverse event). She consulted her doctor and was prescribed a steroid shot, a 6-day regimen of prednisone where it tapers off every day, and a muscle relaxant. When paraphrased the concern, consumer stated, yes and he does not think that the issue was her osteoporosis because she only, she was on a very low scale of that. Consumer stated, she started, okay she was trying to figure out the onset. She got the vaccine Saturday at 11am. She was going to say it was Saturday night, like the late Saturday night, may be 10, she started having a slight back pain. When clarified the other medical condition as osteoporosis, consumer stated, yes, like she said they just started her on it. She means they just found out about it. When clarified that the consumer was taking Prolia for Osteoporosis, consumer stated, yes, they went ahead and gave her Prolia because she cannot take Fosamax because she was allergic to it. They wanted to give her a different medication that they give to early people, but she took one and had an adverse reaction because she has Celiac disease which causes dermatitis (further clarification unknown). She does not know why it has affected her. She had 3 other Pfizer vaccine and it had no reactions. Not even, she means if touched her arm could tell that she has gotten a shot but no redness, no soreness really at all. When again probed for the name of the medication, consumer stated, the one that she was allergic to, she guess she was allergic to it. It caused her break out in dermatitis herpetiformis, which was like the herpes but not sexually transmitted disease. It was a rash and sores. When again clarified the name of the product: Consumer stated, Fosamax, she took one tablet last year and she had a reaction and she said she was not taking it. She could not take that one. Consumer stated, no, that was all. She would like someone to call her and tell her what they think that this was a temporary thing. She mean at least if other people have had this, you know it was rare but there was documentations. She mentioned that she did also look up Guillain-Barre syndrome and was thinking that symptoms from the vaccine might be a precursor to multiple sclerosis. She describes herself as a very healthy, and natural person who does not take that many medications. The patient underwent the following laboratory tests and procedures: Laboratory Test: Everything was normal, notes: Normal. The action taken for alendronate sodium was dosage permanently withdrawn. Therapeutic measures were taken as a result of back pain, swelling, dysstasia.  Follow-up attempts are completed. No further information is expected.