Became extremely disorientated; Fingers started to swell and doubled the size/ Fingers so swollen; Developed pain in the hands/painful/pain is more on top hand than palm and under fingers/ pain fingers like pin sticking into them; Tingling in the fingers; Can't sleep; Can't sit; Can't eat; Legs are weak; Numbness and tingling in the fingers; Can't move around/ he could not bend or move them; Back and back of arm started itching; Patient could not walk due to an atrophy in the legs; Walking very very slowly/could not walk; This spontaneous case was reported by a consumer and describes the occurrence of ATROPHY (Patient could not walk due to an atrophy in the legs), GAIT DISTURBANCE (Walking very very slowly/could not walk) and MOVEMENT DISORDER (Can't move around/ he could not bend or move them) in a 90-year-old male patient who received mRNA-1273 (Moderna COVID-19 Vaccine) for COVID-19 vaccination. The occurrence of additional non-serious events is detailed below.     No Medical History information was reported.   On 08-Jan-2021, the patient received first dose of mRNA-1273 (Moderna COVID-19 Vaccine) (Intramuscular) 1 dosage form. On 15-Feb-2021, received second dose of mRNA-1273 (Moderna COVID-19 Vaccine) (Intramuscular) dosage was changed to 1 dosage form. On 25-Oct-2021, received third dose of mRNA-1273 (Moderna COVID-19 Vaccine) (Intramuscular) dosage was changed to 1 dosage form. On 20-Nov-2021, the patient experienced ATROPHY (Patient could not walk due to an atrophy in the legs) (seriousness criterion disability), GAIT DISTURBANCE (Walking very very slowly/could not walk) (seriousness criterion disability) and PRURITUS (Back and back of arm started itching). On an unknown date, the patient experienced MOVEMENT DISORDER (Can't move around/ he could not bend or move them) (seriousness criterion disability), DISORIENTATION (Became extremely disorientated), PERIPHERAL SWELLING (Fingers started to swell and doubled the size/ Fingers so swollen), PAIN IN EXTREMITY (Developed pain in the hands/painful/pain is more on top hand than palm and under fingers/ pain fingers like pin sticking into them), PARAESTHESIA (Tingling in the fingers), INSOMNIA (Can't sleep), SITTING DISABILITY (Can't sit), EATING DISORDER (Can't eat), MUSCULAR WEAKNESS (Legs are weak) and HYPOAESTHESIA (Numbness and tingling in the fingers). The patient was treated with PREDNISONE at a dose of UNK UNK, one time dose and DICLOFENAC (VOLTAREN [DICLOFENAC]) (topical) at an unspecified dose and frequency. At the time of the report, ATROPHY (Patient could not walk due to an atrophy in the legs), GAIT DISTURBANCE (Walking very very slowly/could not walk), MOVEMENT DISORDER (Can't move around/ he could not bend or move them), PRURITUS (Back and back of arm started itching), DISORIENTATION (Became extremely disorientated), PERIPHERAL SWELLING (Fingers started to swell and doubled the size/ Fingers so swollen), PAIN IN EXTREMITY (Developed pain in the hands/painful/pain is more on top hand than palm and under fingers/ pain fingers like pin sticking into them), PARAESTHESIA (Tingling in the fingers), INSOMNIA (Can't sleep), SITTING DISABILITY (Can't sit), EATING DISORDER (Can't eat), MUSCULAR WEAKNESS (Legs are weak) and HYPOAESTHESIA (Numbness and tingling in the fingers) outcome was unknown.      DIAGNOSTIC RESULTS (normal ranges are provided in parenthesis if available): On an unknown date, Blood test: not reported (Inconclusive) Not reported. On an unknown date, Computerised tomogram: not reported (Inconclusive) not determined what patient has.         No concomitant medications were reported.  On 20-Nov-2021, back and back of arm started itching, and patient could not walk due to an atrophy in the legs. He also became extremely disorientated, and his fingers swelled, doubling the size. He went to three different HCPs, had bloodwork and CT scan done. He was checked from head to toe but it was not determined what patient had. Then, patient was walking very slowly. He took 6 pills PREDNISONE over 6 days. He felt better. He also applied VOLTAREN cream in hands.  By the 20 Nov 2021, patient was so disoriented, pain fingers like pin sticking into them. Fingers so swollen and he could not bend or move them.  Company Comment: This case concerns a 90-year-old, male patient with no relevant medical history reported, who experienced the unexpected events of atrophy, gait disturbance and movement disorder. The events occurred 26 days after the third dose of mRNA-1273. The rechallenge was not applicable since the events happened after the third dose. Patient´s age remains a confounder. The benefit-risk relationship of mRNA-1273 is not affected by this report.   Most recent FOLLOW-UP information incorporated above includes: On 09-Jan-2022: Follow-up received on 10-Jan-2022 contains event verbatim of movement disorder, peripheral swelling, pain in extremity and narrative was updated.; Sender's Comments: This case concerns a 90-year-old, male patient with no relevant medical history reported, who experienced the unexpected events of atrophy, gait disturbance and movement disorder. The events occurred 26 days after the third dose of mRNA-1273. The rechallenge was unknown since no information about the first dose was disclosed. Patient´s age remains a confounder. The benefit-risk relationship of mRNA-1273 is not affected by this report.