Transverse myelitis with progression of symptoms; Interchange of vaccine products; Revaccination with different vacine; This literature-non-study case was reported in a literature article and describes the occurrence of MYELITIS TRANSVERSE (Transverse myelitis with progression of symptoms) in a 78-year-old female patient who received mRNA-1273 (Moderna COVID-19 Vaccine) for COVID-19 prophylaxis. The occurrence of additional non-serious events is detailed below.    Co-suspect products included non-company products FAMTOZINAMERAN, TOZINAMERAN (PFIZER BIONTECH COVID-19 VACCINE, BIVALENT (ORIGINAL AND OMICRON BA.4/5)) for an unknown indication and INFLUENZA VACCINE (INFLUENZA VIRUS VACCINE) for an unknown indication.    Concurrent medical conditions included Atrial fibrillation, Hypertension, Hyperlipidemia and Osteoporosis.   In December 2020, the patient received dose of mRNA-1273 (Moderna COVID-19 Vaccine) (unknown route) 1 dosage form. In January 2021, received dose of mRNA-1273 (Moderna COVID-19 Vaccine) (unknown route) dosage was changed to 1 dosage form. In October 2021, the patient received dose of FAMTOZINAMERAN, TOZINAMERAN (PFIZER BIONTECH COVID-19 VACCINE, BIVALENT (ORIGINAL AND OMICRON BA.4/5)) (unknown route) 1 dosage form. In April 2022, received dose of FAMTOZINAMERAN, TOZINAMERAN (PFIZER BIONTECH COVID-19 VACCINE, BIVALENT (ORIGINAL AND OMICRON BA.4/5)) (unknown route) dosage was changed to 1 dosage form. In September 2022, the patient received dose of INFLUENZA VACCINE (INFLUENZA VIRUS VACCINE) (unknown route) 1 dosage form. On an unknown date, the patient experienced MYELITIS TRANSVERSE (Transverse myelitis with progression of symptoms) (seriousness criteria hospitalization and medically significant), INTERCHANGE OF VACCINE PRODUCTS (Interchange of vaccine products) and COVID-19 IMMUNISATION (Revaccination with different vacine). The patient was treated with METHYLPREDNISOLONE (intravenous) at a dose of 1 gram, daily, for 5 days. At the time of the report, MYELITIS TRANSVERSE (Transverse myelitis with progression of symptoms) was resolving and INTERCHANGE OF VACCINE PRODUCTS (Interchange of vaccine products) and COVID-19 IMMUNISATION (Revaccination with different vacine) outcome was unknown.      DIAGNOSTIC RESULTS (normal ranges are provided in parenthesis if available): On an unknown date, Angiotensin converting enzyme: (Negative) ACE level negative. On an unknown date, Antinuclear antibody: Within normal limits. On an unknown date, Babinski reflex test: (Positive) Babinski sign was Positive. On an unknown date, Blood creatine phosphokinase: Within normal limits. On an unknown date, C-reactive protein: Within normal limits. On an unknown date, CSF test: Including anti-MOG and anti-AQP4 antibodies, and oligoclonal bands was negative. On an unknown date, Magnetic resonance imaging: Non-specific, non-enhancing lesion with T2 hyperintensity at T5-6 and Left parasagittal and posterior cord signal abnormality at T5-T6 with t2-hyperintensity and pathologic contrast enhancement.. On an unknown date, Magnetic resonance imaging head: Unremarkable. On an unknown date, Physical examination: strength was 4/5 for flexion and extension of the hip and knee, sensation to light touch was diffusely decreased. On an unknown date, Red blood cell sedimentation rate: Within normal limits. On an unknown date, Vitamin B12: Within normal limits.     For mRNA-1273 (Moderna COVID-19 Vaccine) (Unknown), the reporter did not provide any causality assessments.   The patient denies any recent infectious event and common infectious symptoms.  Initial MRI of her spinal cod lesion was non-enhancing and non-specific. Given progression of symptoms and lack of an alternative diagnosis, repeat imaging was obtained which demonstrated an enhanced lesion consist with TM. Para infectious and post-vaccination myelitis often have nonspecific findings on MRI.   Reporter did not allow further contact  Company comment: This is a literature non-study case concerning a 78-year-old female patient with Concurrent medical conditions of Atrial fibrillation, Hypertension, Hyperlipidemia and Osteoporosis, who experienced the unexpected serious AESI myelitis transverse (seriousness criteria hospitalization and medically significant). Non serious events of Interchange of vaccine products and Revaccination with different COVID-19 vaccine were noted in the case. The patient was walking when she felt lightheaded and developed left thigh tingling followed by left leg weakness. She presented the next day unable to walk independently. On Physical examination disclosed strength of 4/5 for flexion and extension of the hip and knee and sensation to light touch was diffusely decreased, and Babinsky sign was positive. Initial Spinal MRI showed Non-specific, non-enhancing lesion with T2 hyperintensity at T5-6. All lab tests resulted negative but due to progression of symptoms including urine retention, another MRI was repeated on hospital day 10 which disclosed Left parasagittal and posterior cord signal abnormality at T5-T6 with t2-hyperintensity and pathologic contrast enhancement. Patient denies any recent infectious event and common infectious symptoms. Initial MRI of her spinal cord lesion was non-enhancing and non-specific. Given progression of symptoms and lack of an alternative diagnosis, repeat imaging was obtained which demonstrated an enhanced lesion consist with TM. The events occurred after receiving a dose of mRNA-1273 vaccine (event dates were not provided). The patient received the first and second doses of the Moderna vaccine and then, received the third and fourth doses of the famtozinameran, tozinameran (Pfizer Biontech COVID-19 vaccine). The patient also received a dose of the Influenza virus vaccine. The symptoms started 6 days after receiving the bivalent Pfizer-BioNTech booster and seasonal influenza vaccine. The patient was treated with methylprednisolone (intravenous) for 5 days. Concomitant medications were not reported. The outcome of the event myelitis transverse was reported as resolving.  The benefit-risk relationship of mRNA-1273 vaccine is not affected by this report.; Sender's Comments: Company comment: This is a literature non-study case concerning a 78-year-old female patient with Concurrent medical conditions of Atrial fibrillation, Hypertension, Hyperlipidemia and Osteoporosis, who experienced the unexpected serious AESI myelitis transverse (seriousness criteria hospitalization and medically significant). Non serious events of Interchange of vaccine products and Revaccination with different COVID-19 vaccine were noted in the case. The patient was walking when she felt lightheaded and developed left thigh tingling followed by left leg weakness. She presented the next day unable to walk independently. On Physical examination disclosed strength of 4/5 for flexion and extension of the hip and knee and sensation to light touch was diffusely decreased, and Babinsky sign was positive. Initial Spinal MRI showed Non-specific, non-enhancing lesion with T2 hyperintensity at T5-6. All lab tests resulted negative but due to progression of symptoms including urine retention, another MRI was repeated on hospital day 10 which disclosed Left parasagittal and posterior cord signal abnormality at T5-T6 with t2-hyperintensity and pathologic contrast enhancement. Patient denies any recent infectious event and common infectious symptoms. Initial MRI of her spinal cord lesion was non-enhancing and non-specific. Given progression of symptoms and lack of an alternative diagnosis, repeat imaging was obtained which demonstrated an enhanced lesion consist with TM. The events occurred after receiving a dose of mRNA-1273 vaccine (event dates were not provided). The patient received the first and second doses of the Moderna vaccine and then, received the third and fourth doses of the famtozinameran, tozinameran (Pfizer Biontech COVID-19 vaccine). The patient also received a dose of the Influenza virus vaccine. The symptoms started 6 days after receiving the bivalent Pfizer-BioNTech booster and seasonal influenza vaccine. The patient was treated with methylprednisolone (intravenous) for 5 days. Concomitant medications were not reported. The outcome of the event myelitis transverse was reported as resolving.  The benefit-risk relationship of mRNA-1273 vaccine is not affected by this report.