Pulmonary embolism; Atrial fibrillation with rapid ventricular response; Cardiac arrest; Multi-organ dysfunction; Transverse myelitis; This literature-non-study case was reported in a literature article and describes the occurrence of MYELITIS TRANSVERSE (Transverse myelitis), PULMONARY EMBOLISM (Pulmonary embolism), ATRIAL FIBRILLATION (Atrial fibrillation with rapid ventricular response), CARDIAC ARREST (Cardiac arrest) and MULTI-ORGAN DISORDER (Multi-organ dysfunction) in a 58-year-old male patient who received mRNA-1273 (Moderna COVID-19 Vaccine) for COVID-19 vaccination.   The patient's past medical history included Chronic back pain (placement of a spinal stimulator in 1990), Chemotherapy (underwent four cycles of chemotherapy with Atezolizumab, Carboplatin and Etoposide which was completed on 25-March-2021. Thereafter, he was administered Atezolizumab as maintenance infusion on 12-May-2021.), Spinal nerve stimulator implantation (spinal stimulator) in 1990 and Radiotherapy to brain (whole brain radiation). Concurrent medical conditions included Small cell lung cancer metastatic (stage 4 with metastasis to the liver and bone,) since December 2020, Hypertension and Benign prostatic hyperplasia. Concomitant products included ATEZOLIZUMAB for Small cell lung cancer.   On 11-May-2021, the patient received first dose of mRNA-1273 (Moderna COVID-19 Vaccine) (unknown route) 1 dosage form. On 07-Jun-2021, received second dose of mRNA-1273 (Moderna COVID-19 Vaccine) (unknown route) dosage was changed to 1 dosage form. On 08-Jun-2021, the patient experienced MYELITIS TRANSVERSE (Transverse myelitis) (seriousness criteria hospitalization and medically significant). On an unknown date, the patient experienced PULMONARY EMBOLISM (Pulmonary embolism) (seriousness criteria hospitalization and medically significant), ATRIAL FIBRILLATION (Atrial fibrillation with rapid ventricular response) (seriousness criteria hospitalization and medically significant), CARDIAC ARREST (Cardiac arrest) (seriousness criteria hospitalization and medically significant) and MULTI-ORGAN DISORDER (Multi-organ dysfunction) (seriousness criterion hospitalization). The patient was treated with METHYLPREDNISOLONE for Myelitis transverse, at an unspecified dose and frequency. At the time of the report, MYELITIS TRANSVERSE (Transverse myelitis) was resolving and PULMONARY EMBOLISM (Pulmonary embolism), ATRIAL FIBRILLATION (Atrial fibrillation with rapid ventricular response), CARDIAC ARREST (Cardiac arrest) and MULTI-ORGAN DISORDER (Multi-organ dysfunction) outcome was unknown.      DIAGNOSTIC RESULTS (normal ranges are provided in parenthesis if available): On an unknown date, Anti-aquaporin-4 antibody: unremarkable anti-aquaporin receptor 4 (AQP4) antibodies, was unremarkable. On an unknown date, Antibody test: unremarkable serum anti-myelin oligodendrocyte glycoprotein (MOG)  was unremarkable. On an unknown date, Bacterial test: negative (Negative) negative. On an unknown date, Blood creatinine: 2.01 laboratory data was significant for an acute kidney  injury with creatinine 2.01. On an unknown date, Blood test: unremarkable complete blood count was unremarkable.. On an unknown date, CSF test: abnormal (abnormal) 25 white blood cells, 116/µL red blood cells, 94mg/dL protein, normal  glucose, negative oligoclonal bands and normal IgG index.. On an unknown date, Cardiac electrophysiologic study: absent right peroneal motor and sural responses Electrophysiological studies demonstrated absent right peroneal motor and sural responses which are likely secondary to technical limitations from swelling and the patient's inability to move both legs, but superimposed polyneuropathy could not be excluded.. On an unknown date, Magnetic resonance imaging head: abnormal (abnormal) MRI of the brain revealed small enhancing  lesions in the left frontal lobe and both occipital lobes  that were concerning for metastatic disease. On an unknown date, Magnetic resonance imaging spinal: abnormal (abnormal) MRI of the spinal cord, done after  removal of his spinal cord stimulator, showed a large  gadolinium-enhancing lesion in the cervicothoracic  cord spanning from C7 to T7 concerning for LETM. On an unknown date, Neurological examination: deep tendon reflexes in the lower extremities were Deep tendon reflexes in the lower extremities were absent bilaterally and there were no pathological reflexes and abnormal (abnormal) bilateral lower extremity weakness (grade 0/5), and diminished sensation to all modalities belowthe left T4 and the right T5 sensory dermatome. On an unknown date, Urine analysis: unremarkable unremarkable. On an unknown date, Viral test: negatives (Negative) Human parechoviruses,enterovirus, CMV, HSV 1 and 2, VZV and HHV6  were all negatives.     For mRNA-1273 (Moderna COVID-19 Vaccine) (Unknown), the reporter considered MYELITIS TRANSVERSE (Transverse myelitis), PULMONARY EMBOLISM (Pulmonary embolism), ATRIAL FIBRILLATION (Atrial fibrillation with rapid ventricular response), CARDIAC ARREST (Cardiac arrest) and MULTI-ORGAN DISORDER (Multi-organ dysfunction) to be related.    Patient presented to the hospital with acute onset lower extremity weakness and loss of sensation from his chest down to his lower extremities. The patient noticed the symptoms 2 days prior, soon after he woke up from sleep. In addition, he also had urinary retention requiring foley catheter placement. He did not have a history of prior trauma or a preceding viral infection. Deep tendon reflexes in the lower extremities were absent bilaterally and there were no pathological reflexes.   Patient had 5-day course of pulsed methylprednisolone was initiated, followed by therapeutic plasma exchange for 3 days total on alternating days. The patient experienced minimal improvement in the neurologic exam with increased strength in his lower extremities to grade 1/5 however the sensory level remained unchanged. His hospital course was complicated by development of pulmonary embolism and atrial fibrillation with rapid ventricular response. On day 24 of his hospitalization, he suffered a cardiac arrest in the setting of advanced malignancy and multi-organ dysfunction.  Company Comment:  This literature-non-study case concerns a 58-year-old male patient, with medical history of chemotherapy with Atezolizumab as maintenance infusion for small cell lung cancer, who experienced the serious (due to medically significant and hospitalization) unexpected events of MYELITIS TRANSVERSE, PULMONARY EMBOLISM, ATRIAL FIBRILLATION, CARDIAC ARREST and MULTI-ORGAN DISORDER, after the second dose of mRNA-1273 vaccine. He consulted for lower extremity weakness, loss of sensation, and urinary retention, on the following day of the vaccination. A neurological examination revealed bilateral lower extremity weakness, diminished sensation and absence of deep tendon reflexes. The analysis of cerebrospinal fluid showed elevated white blood cells, but was negative for bacteria and viruses, and a magnetic resonance imaging revealed a longitudinally extensive transverse myelitis lesion in the cord. He received methylprednisolone followed by therapeutic plasma exchange as treatment with minimal improvement, but his hospital course was complicated by development of pulmonary embolism and atrial fibrillation followed by cardiac arrest and multi-organ dysfunction. The recent chemotherapy with Atezolizumab remains a confounder for myelitis transverse. The benefit-risk relationship of the mRNA-1273 is not affected by this report.   Most recent FOLLOW-UP information incorporated above includes: On 14-Apr-2022: Follow up received by safety on 15-Apr-2022 has Email with full text article received from team and contains significant information, Author address added, Citation details updated (additional authors added, year of publication), Patient identifier provided, past medical history reported, past drug therapy reported, dose 1 and dose 2 start date provided, Lab data provided, event outcome provided, Hospitalization added as an additional seriousness criteria, additional events added.; Sender's Comments: This literature-non-study case concerns a 58-year-old male patient, with medical history of chemotherapy with Atezolizumab as maintenance infusion for small cell lung cancer, who experienced the serious (due to medically significant and hospitalization) unexpected events of MYELITIS TRANSVERSE, PULMONARY EMBOLISM, ATRIAL FIBRILLATION, CARDIAC ARREST and MULTI-ORGAN DISORDER, after the second dose of mRNA-1273 vaccine. He consulted for lower extremity weakness, loss of sensation, and urinary retention, on the following day of the vaccination. A neurological examination revealed bilateral lower extremity weakness, diminished sensation and absence of deep tendon reflexes. The analysis of cerebrospinal fluid showed elevated white blood cells, but was negative for bacteria and viruses, and a magnetic resonance imaging revealed a longitudinally extensive transverse myelitis lesion in the cord. He received methylprednisolone followed by therapeutic plasma exchange as treatment with minimal improvement, but his hospital course was complicated by development of pulmonary embolism and atrial fibrillation followed by cardiac arrest and multi-organ dysfunction. The recent chemotherapy with Atezolizumab remains a confounder for myelitis transverse. The benefit-risk relationship of the mRNA-1273 is not affected by this report.