They told her they could not find any blood clot but that, she might have sprained it or something; pain that started in her left leg, is now in both legs/pain moved into both legs; she can't walk/she can barely walk; Her leg was swollen and they could not find any blood clots; Started with left knee and now it is both knees and both thighs and going up to both hips; This is a spontaneous report received from contactable reporter(s) (Consumer or other non HCP) from medical information team. The reporter is the patient.  A 53-year-old female patient received BNT162b2 (BNT162B2), on 19May2022 as dose 1, single (Lot number: FM9992) at the age of 53 years, in left arm for covid-19 immunisation. The patient's relevant medical history included: "COVID-19" (unspecified if ongoing), notes: had Covid twice, thought she better get the vaccine because she works with the public. There were no concomitant medications. The following information was reported: LIGAMENT SPRAIN (non-serious), outcome "not recovered", described as "They told her they could not find any blood clot but that, she might have sprained it or something"; PAIN IN EXTREMITY (non-serious), outcome "not recovered", described as "pain that started in her left leg, is now in both legs/pain moved into both legs"; GAIT DISTURBANCE (non-serious), outcome "not recovered", described as "she can't walk/she can barely walk"; PERIPHERAL SWELLING (non-serious), outcome "not recovered", described as "Her leg was swollen and they could not find any blood clots"; ARTHRALGIA (non-serious), outcome "not recovered", described as "Started with left knee and now it is both knees and both thighs and going up to both hips". The events "they told her they could not find any blood clot but that, she might have sprained it or something", "pain that started in her left leg, is now in both legs/pain moved into both legs", "she can't walk/she can barely walk", "her leg was swollen and they could not find any blood clots" and "started with left knee and now it is both knees and both thighs and going up to both hips" required physician office visit and emergency room visit. Therapeutic measures were taken as a result of ligament sprain, pain in extremity, gait disturbance, peripheral swelling, arthralgia.  Additional Information: Caller states she took first shot of the Pfizer Covid vaccine 19May2022. By 21May2022, was at the hospital, thinking she had a blood clot in her leg because something was wrong with her left leg. They told her they could not find any blood clot but that, she might have sprained it or something. She has not done anything to it, just had the shot on 19May2022. Has been to the hospital twice since then. Started with her left leg hurting and now it has moved into both legs and she can barely walk. Is that due to that vaccine patient asked. There is no other reason for her to be hurting like this and she can barely walk. Treatment: They put her on some anti inflammatory medicines and some type of pain medication which was not helping with the pain and they are not doing anything for it. Caller provided names of Medications as Tylenol 3 with Codeine, Hydrocodone, Gabapentin, Meloxicam and Indomethacin. NDC, LOT, EXP for Tylenol 3 with Codeine, Hydrocodone, Gabapentin, Meloxicam and Indomethacin: Unknown. Gabapentin has discard date of 23Jun2023.