muscle weakness; Fatigue; myalgias / myalgia-type reaction; primary non-specific myopathy; paralyzation; inability to walk; Muscle fatigue; Information has been received from a physician concerning a 16-year-old Caucasian female with a history of mononucleosis and knee injuries who on 14-AUG-1998 was vaccinated with a second dose of hepatitis B Vaccine (Recombinant) (manufacturer unknown). Two to three weeks post-vaccination, the patient experienced muscle weakness in her legs and deltoids, myalgia and extreme fatigue. In addition, the physician felt that it was "unclear whether adverse experiences were related to the immunization." The physician felt the symptoms were disabling. The results of a muscle biopsy were pending. The symptoms persisted at the time of the report. The symptoms were considered disabling. Follow-up was received from a physician. A muscle biopsy from the patient's right quadriceps was suggestive of a "primary, non-specific myopathy". The biopsy revealed a wide scattering of myofiber diameters between too small and too large for age and location suggestive of primary myopathy, whether dystrophic or mitochondrial. Artifactu al freezing-induced changes in the biopsy rendered difficult any further interpretation of histological features. No specific tubular or nemaline inclusions and no myofiber necrosis or ragged-red fibers were seen. Cross, oblique and longitudinal sections of muscle showed variation in myofiber sizes with a scattering of cross myofiber diameters between 25-130 micrometers. No endomysial fibrosis and no inflammatory infiltrates were seen. No storage material, amyloid deposits or any specific inclusions were identified. Frozen myofibers were artifactually vacuolated and were difficult to evaluate. A few lobulated fibers were noted in the oxidative enzyme stain. No fiber type grouping or fiber-type predominance was evident.  Follow up information was received from the patient on 12-MAR-2021. The patient ha no concomitant Medication. patient's pertinent medical history included tubes in ears as a baby, torn anterior cruciate ligament (ACL) and drug reactions or allergies to sulfa.   On 17-SEP-1998, the patient was vaccinated with the second dose of hepatitis B Vaccine (Recombinant) (manufacturer unknown) injection in arm, lot number 1224E has been verified to be a valid lot number for hepatitis B Vaccine (Recombinant), expiration date reported as February 2000, but upon internal validation established as 07-FEB-2000 for prophylaxis reported as "in preparation for college" (dose and route of administration were not reported).  On 17-SEP-1998 (also reported as "approximately two days later" (conflicting information)), the patient began experiencing muscle fatigue, myalgia-type reaction, and paralyzation/inability to walk for approximately 9 months (muscle fatigue, paralysis and gait inability). The patient received aqua therapy for mobility and strength. The date of administration of the first dose was unknown. On an unknown date, the patient had performed the following laboratory tests: unspecified bloodwork, electrocardiogram (EKG), neuromuscular tests, magnetic resonance imaging (MRI), Cat Scans and the results were not provided. It was reported that the patient saw several physicians and specialists.  The patient reported being partially recovered presently but only had about 50% of her strength back and had a hard time working full time. The reporter considered the events muscle fatigue, paralysis and gait inability to be related to hepatitis B Vaccine (Recombinant) (manufacturer unknown).   Upon internal review, the events were determined to be serious per disability.