Longitudinal extensive transverse myelitis; This literature-non-study case was reported in a literature article and describes the occurrence of MYELITIS TRANSVERSE (Longitudinal extensive transverse myelitis) in a 60-year-old male patient who received mRNA-1273 (Spikevax) for COVID-19 prophylaxis.       Concurrent medical conditions included Stroke (chronic right hemisphere stroke) and Hemiparesis (left) (residual left hemiparesis).    On an unknown date, the patient received second dose of mRNA-1273 (Spikevax) (unknown route) 1 dosage form. On an unknown date,  after starting mRNA-1273 (Spikevax), the patient experienced MYELITIS TRANSVERSE (Longitudinal extensive transverse myelitis) (seriousness criteria hospitalization and medically significant). The patient was hospitalized for 4 days due to MYELITIS TRANSVERSE. The patient was treated with METHYLPREDNISOLONE for Myelitis transverse, at a dose of 1000 milligram once a day. At the time of the report, MYELITIS TRANSVERSE (Longitudinal extensive transverse myelitis) was resolving.      DIAGNOSTIC RESULTS (normal ranges are provided in parenthesis if available): On an unknown date, Antibody test: (Negative) Negative and (Negative) Negative. On an unknown date, Antiribosomal P antibody: unremarkable. On an unknown date, C-reactive protein: Mildly elevated. On an unknown date, CSF glucose: 124. On an unknown date, CSF protein: 55. On an unknown date, CSF red blood cell count: 1271. On an unknown date, CSF white blood cell count: 5. On an unknown date, Double stranded DNA antibody: unremarkable. On an unknown date, HIV test: unremarkable. On an unknown date, HTLV test: unremarkable. On an unknown date, Herpes simplex test: unremarkable. On an unknown date, Magnetic resonance imaging: MRI spine revealed a longitudinally-extensive, non-enhancing T2-hyperintense lesion spanning T8T12. On an unknown date, Physical examination: Examination showed hypotonic lower extremities, proximal greater than distal weakness, a T9 dermatome sensory level, perineal numbness, mildly-reduced rectal tone, and preserved reflexes.. On an unknown date, Red blood cell sedimentation rate: Mildly elevated. On an unknown date, Treponema test: unremarkable and unremarkable. On an unknown date, Varicella virus test: unremarkable. On an unknown date, West Nile virus test: unremarkable.     For mRNA-1273 (Spikevax) (Unknown), the reporter considered MYELITIS TRANSVERSE (Longitudinal extensive transverse myelitis) to be related.    Concomitant medication was not reported.  Patient experienced bilateral lower extremity numbness progressing to weakness and urinary and bowel incontinence 10 days after receiving his second Moderna SARS-CoV-2 vaccination.  Extensive serum and CSF work-up for other causes of myelopathy, including nutritional/toxic (copper, zinc, heavy metals) and rheumatologic (anti-Jo, anti-Mi-2, anti-Ro/La, anti-smith, anti-Scleroderma, anti-RNP), were unremarkable. Patient improved with methylprednisolone for 5 days suggesting an autoimmune etiology.  This literature-non-study case concerns a 60-year-old, male patient with medical history of Chronic Right hemisphere Stroke with residual Left hemiparesis, who experienced the unexpected, serious (hospitalization and medically significant) AESI of myelitis transverse (longitudinally-extensive transverse myelitis, defined as 'a lesion spanning three or more vertebral segments on imaging'). The event occurred 10 days after receiving the second dose of the mRNA-1273 vaccine. The patient was admitted for 4 days due to bilateral lower extremity numbness which progressed to weakness, and urinary and bowel incontinence. Physical examination showed hypotonic lower extremities, proximal weakness greater than distal weakness, a T9 dermatome sensory level, perineal numbness, mildly-reduced rectal tone, and preserved reflexes. The Magnetic Resonance Imaging of the Spine revealed a longitudinally-extensive, non-enhancing T2-hyperintense lesion spanning T8 to T12. The Cerebrospinal fluid (CSF) analysis was inconclusive (white blood cells: 5, red blood cells: 1,271, glucose: 124, and protein: 55) while the Erythrocyte sedimentation rate and C-reactive protein were mildly elevated (values were not provided). Extensive serum and CSF work-up for other causes of myelopathy were done. These include: 1) Nutritional/toxic (copper, zinc, heavy metals), 2) Infectious (Rapid Plasma Reagin/Venereal Disease Research Laboratory [RPR/VDRL] serologic test for Syphilis, Human Immunodeficiency virus [HIV], Human T-lymphotropic virus [HTLV], Herpes Simplex virus [HSV], Varicella-Zoster virus [VZV], West Nile virus), and 3) Rheumatologic (anti-Jo [myositis-specific autoantibody], anti-Mi-2 [dermatomyositis-specific autoantibody], anti-Ro/anti-La [antibodies in primary Sjögren's syndrome], anti-smith, anti-dsDNA and antiribosomal P [antibodies specific to Systemic Lupus Erythematosus], anti-Ribonucleoprotein [antibody associated with myositis and lupus], anti-Scleroderma). The results were reported as unremarkable. The anti-neuromyelitis optica (anti-NMO) and anti-myelin oligodendrocyte glycoprotein (anti-MOG) antibodies were negative. The patient was treated with methylprednisolone 1,000 mg daily for 5 days. The patient had improved which suggested an autoimmune etiology. The authors stated that given the timing of the patient's symptom onset after vaccination and thorough exclusion of other causes, they postulate a potentially novel case of Transverse Myelitis (TM) associated with the Moderna SARS-CoV-2 vaccine. The authors also stated that although post-vaccination myelopathy is potentially debilitating if untreated, it is rare, and the benefits of vaccination appear to outweigh the risks. Of note, the medical history of Chronic Right hemisphere Stroke with residual Left hemiparesis may be confused with the presentation of TM (lower extremity numbness which progressed to weakness). However, the various diagnostic tests and treatment suggested an autoimmune etiology which is different from the pathophysiology of stroke. The benefit-risk relationship of the mRNA-1273 vaccine is not affected by this report.; Sender's Comments: This literature-non-study case concerns a 60-year-old, male patient with medical history of Chronic Right hemisphere Stroke with residual Left hemiparesis, who experienced the unexpected, serious (hospitalization and medically significant) AESI of myelitis transverse (longitudinally-extensive transverse myelitis, defined as 'a lesion spanning three or more vertebral segments on imaging'). The event occurred 10 days after receiving the second dose of the mRNA-1273 vaccine. The patient was admitted for 4 days due to bilateral lower extremity numbness which progressed to weakness, and urinary and bowel incontinence. Physical examination showed hypotonic lower extremities, proximal weakness greater than distal weakness, a T9 dermatome sensory level, perineal numbness, mildly-reduced rectal tone, and preserved reflexes. The Magnetic Resonance Imaging of the Spine revealed a longitudinally-extensive, non-enhancing T2-hyperintense lesion spanning T8 to T12. The Cerebrospinal fluid (CSF) analysis was inconclusive (white blood cells: 5, red blood cells: 1,271, glucose: 124, and protein: 55) while the Erythrocyte sedimentation rate and C-reactive protein were mildly elevated (values were not provided). Extensive serum and CSF work-up for other causes of myelopathy were done. These include: 1) Nutritional/toxic (copper, zinc, heavy metals), 2) Infectious (Rapid Plasma Reagin/Venereal Disease Research Laboratory [RPR/VDRL] serologic test for Syphilis, Human Immunodeficiency virus [HIV], Human T-lymphotropic virus [HTLV], Herpes Simplex virus [HSV], Varicella-Zoster virus [VZV], West Nile virus), and 3) Rheumatologic (anti-Jo [myositis-specific autoantibody], anti-Mi-2 [dermatomyositis-specific autoantibody], anti-Ro/anti-La [antibodies in primary Sjögren's syndrome], anti-smith, anti-dsDNA and antiribosomal P [antibodies specific to Systemic Lupus Erythematosus], anti-Ribonucleoprotein [antibody associated with myositis and lupus], anti-Scleroderma). The results were reported as unremarkable. The anti-neuromyelitis optica (anti-NMO) and anti-myelin oligodendrocyte glycoprotein (anti-MOG) antibodies were negative. The patient was treated with methylprednisolone 1,000 mg daily for 5 days. The patient had improved which suggested an autoimmune etiology. The authors stated that given the timing of the patient's symptom onset after vaccination and thorough exclusion of other causes, they postulate a potentially novel case of Transverse Myelitis (TM) associated with the Moderna SARS-CoV-2 vaccine. The authors also stated that although post-vaccination myelopathy is potentially debilitating if untreated, it is rare, and the benefits of vaccination appear to outweigh the risks. Of note, the medical history of Chronic Right hemisphere Stroke with residual Left hemiparesis may be confused with the presentation of TM (lower extremity numbness which progressed to weakness). However, the various diagnostic tests and treatment suggested an autoimmune etiology which is different from the pathophysiology of stroke. The benefit-risk relationship of the mRNA-1273 vaccine is not affected by this report.