Unable to walk/ unable to get out of his chair/Mobility problems described above which led to a hospitalization; Profuse sweating; Pain in his legs; Temperature of 101 degrees Farenheight/ fever; This spontaneous case was reported by a consumer and describes the occurrence of GAIT INABILITY (Unable to walk/ unable to get out of his chair/Mobility problems described above which led to a hospitalization) in an 88-year-old male patient who received mRNA-1273 (Moderna COVID-19 Vaccine) (batch nos. 033K21-2A, 071F21A, 029K20A and 011J20A) for COVID-19 vaccination. The occurrence of additional non-serious events is detailed below.     The patient's past medical history included Dementia.   On 30-Dec-2020, the patient received first dose of mRNA-1273 (Moderna COVID-19 Vaccine) (unknown route) 1 dosage form. On 27-Jan-2021, received second dose of mRNA-1273 (Moderna COVID-19 Vaccine) (unknown route) dosage was changed to 1 dosage form. On 27-Oct-2021, received third dose of mRNA-1273 (Moderna COVID-19 Vaccine) (unknown route) dosage was changed to 1 dosage form. On 18-Apr-2022, received fourth dose of mRNA-1273 (Moderna COVID-19 Vaccine) (unknown route) dosage was changed to 1 dosage form. On 19-Apr-2021, the patient experienced GAIT INABILITY (Unable to walk/ unable to get out of his chair/Mobility problems described above which led to a hospitalization) (seriousness criterion hospitalization), HYPERHIDROSIS (Profuse sweating), PAIN IN EXTREMITY (Pain in his legs) and PYREXIA (Temperature of 101 degrees Farenheight/ fever). The patient was hospitalized from 19-Apr-2022 to 20-Apr-2022 due to GAIT INABILITY. The patient was treated with Physical therapy (Physical Therapy assessment) for Gait inability. At the time of the report, GAIT INABILITY (Unable to walk/ unable to get out of his chair/Mobility problems described above which led to a hospitalization) was resolving and HYPERHIDROSIS (Profuse sweating), PAIN IN EXTREMITY (Pain in his legs) and PYREXIA (Temperature of 101 degrees Farenheight/ fever) outcome was unknown.      DIAGNOSTIC RESULTS (normal ranges are provided in parenthesis if available): On 19-Apr-2022, Body temperature: 101 (High) 101 degrees Farenheight. On 19-Apr-2022, Laboratory test: results not reported Several tests were run and results were not reported..         No concomitant medications were provided.  The patient was unable to get out of his chair and he was unable to walk. The caller picked her husband up out of his lift chair and to his seated walker to bring her husband to the toilet. The patient could not get off the toilet and so the caller had to call the paramedics. The ambulance came and the patient was brought to the hospital. Several tests were run. The patient was well enough to walk on 20-Apr-2022 after a Physical Therapy assessment. The patient was discharged and the Physician at the hospital told the patient that he had a reaction to his second Moderna covid-19 vaccine booster dose and that was what led to his mobility problems of 19-APR-2022.  Company comment:This spontaneous case concerns a 88 year old male patient with underlying medical history of dementia, who experienced the unexpected, serious(Hospitalization) event of Mobility decreased and Gait inability. The events occurred approximately 1 day after receiving a dose of mRNA 1273 as fourth dose of COVID-19 vaccine. AESI of COVID-19. The patient was unable to get out of his chair and he was unable to walk. The patient could not get off the toilet and so the caller had to call the paramedics. The ambulance came and the patient was brought to the hospital. Several tests were run. The patient was well enough to walk on 20Apr2022 after a Physical Therapy assessment.  The clinical course and treatment details were not reported in the case. The benefit-risk relationship of mRNA-1273 is not affected by this report.   This case was linked to US-MODERNATX, INC.-MOD-2022-546935, US-MODERNATX, INC.-MOD-2022-546924, US-MODERNATX, INC.-MOD-2022-546786 (Linked Report).; Sender's Comments: This spontaneous case concerns a 88 year old male patient with underlying medical history of dementia, who experienced the unexpected, serious(Hospitalization) event of Mobility decreased and Gait inability. The events occurred approximately 1 day after receiving a dose of mRNA 1273 as fourth dose of COVID-19 vaccine. AESI of COVID-19. The patient was unable to get out of his chair and he was unable to walk. The patient could not get off the toilet and so the caller had to call the paramedics. The ambulance came and the patient was brought to the hospital. Several tests were run. The patient was well enough to walk on 20Apr2022 after a Physical Therapy assessment.  The clinical course and treatment details were not reported in the case. The benefit-risk relationship of mRNA-1273 is not affected by this report. US-MODERNATX, INC.-MOD-2022-546786:Wife case (1st dose) US-MODERNATX, INC.-MOD-2022-546935:MOD22-012085 (Wife's case-booster dose) US-MODERNATX, INC.-MOD-2022-546924:Wife case (2nd dose)