blood clot; Sciatica; She then got sciatica in her leg and couldn't walk; charley horse in her lower leg while walking; soreness in arm / pain in her foot / lower leg/calf still hurt; This is a spontaneous report from a contactable nurse (patient). This 86 years old female patient received the second single dose of BNT162B2 (PFIZER-BIONTECH COVID-19 VACCINE; lot EN6203) on 04Mar2021 at 11:00, in left arm, for COVID-19 immunisation. No other vaccines were administered on the same date. The patient received the first dose of BNT162B2 vaccine intramuscular, on 11Feb2021 at 18:30 (lot EN6201). The patient received some years ago an unspecified pneumonia vaccine and an unspecified tetanus vaccine experiencing after both headache, swollen arm and rash. She didn't react to the flu vaccine. Her body didn't want any more vaccine. Concomitant medications were none. On an unspecified date in Mar2021, maybe a week or two after the second vaccination, early to mid afternoon, the patient had what felt like a charley horse in her lower leg while walking, but didn't pay any attention to it, just put ice on the leg. She then got sciatica in her leg on 24Apr2021 and couldn't walk; that was what sent her to the hospital as it was getting worse and she went to the hospital because of the pain. She just ignored it for at least a week but she was still having pain after the second week and could hardly walk due to the sciatica in that leg. At the hospital they found she had a blood clot in the calf of her leg on 28Apr2021. She was hospitalized from 28Apr2021 to 02May2021. The doctors in the hospital recommended that she should report her experience even though they didn't know if it was due to the COVID vaccine due to the proximity. The hospital doctors took care of her but her primary care provider knew that she had been in the hospital. The doctors gave her medications in the hospital that helped the pain in her foot and the sciatica but her lower leg/calf still hurt so they decided to do an ultrasound and found a blood clot. The patient still had to give herself injections in the belly for blood thinner to treat the blood clot. The patient also experienced soreness in arm on an unspecified date in 2021. Sciatica required ER visit. Blood clot was resolving. The other events outcome was unknown. The doctor said that there was a possibility that the blood clot could be related to the COVID vaccine, but it may not be related at all.; Sender's Comments: Based on the information provided by the reporter, including a prolonged onset latency of nearly two months, it appears unlikely that BNT162B2 contributed to the reported events. These are likely intercurrent medical conditions in this elderly patient. This case will be reassessed upon receipt of additional information.   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.,Linked Report(s) :PFIZER INC-2021501847 same patient/drug, different vaccine dose/AE