Rheumatoid Arthritis; Myasthenia Gravis; Rashes, muscle weakness and her skin was falling apart on her hands, and she was diagnosed with Dermatomyositis; This spontaneous case was reported by a physician and describes the occurrence of DERMATOMYOSITIS (Rashes, muscle weakness and her skin was falling apart on her hands, and she was diagnosed with Dermatomyositis), RHEUMATOID ARTHRITIS (Rheumatoid Arthritis) and MYASTHENIA GRAVIS (Myasthenia Gravis) in a 41-year-old female patient who received mRNA-1273 (Moderna COVID-19 Vaccine) (batch nos. 017E21A, 043L20A and 025L20A) for COVID-19 prophylaxis.    Co-suspect product included non-company product ETANERCEPT (ENBREL) for Rheumatoid arthritis.    No medical history was reported.  Concomitant products included AZATHIOPRINE, IMMUNOGLOBULIN HUMAN NORMAL (GAMMAGARD) and PYRIDOSTIGMINE for Myasthenia gravis.   On 29-Dec-2020, the patient received first dose of mRNA-1273 (Moderna COVID-19 Vaccine) (unknown route) 1 dosage form. On 26-Jan-2021, received second dose of mRNA-1273 (Moderna COVID-19 Vaccine) (unknown route) dosage was changed to 1 dosage form. On 25-Aug-2021, received third dose of mRNA-1273 (Moderna COVID-19 Vaccine) (unknown route) dosage was changed to 1 dosage form. In January 2022, the patient started ETANERCEPT (ENBREL) (Subcutaneous) 50 milligram once a week. In August 2022, the patient experienced DERMATOMYOSITIS (Rashes, muscle weakness and her skin was falling apart on her hands, and she was diagnosed with Dermatomyositis) (seriousness criteria disability and medically significant). On an unknown date, the patient experienced RHEUMATOID ARTHRITIS (Rheumatoid Arthritis) (seriousness criteria disability and medically significant) and MYASTHENIA GRAVIS (Myasthenia Gravis) (seriousness criteria disability and medically significant). At the time of the report, DERMATOMYOSITIS (Rashes, muscle weakness and her skin was falling apart on her hands, and she was diagnosed with Dermatomyositis) was resolving and RHEUMATOID ARTHRITIS (Rheumatoid Arthritis) and MYASTHENIA GRAVIS (Myasthenia Gravis) had not resolved.      DIAGNOSTIC RESULTS (normal ranges are provided in parenthesis if available): On an unknown date, SARS-CoV-2 test: Positive.     For mRNA-1273 (Moderna COVID-19 Vaccine) (Unknown), the reporter did not provide any causality assessments.   It was reported that the patient feels her illness, Auto Immune Disorders of Myasthenia Gravis and Rheumatoid Arthritis happened after she got Covid and had 2 Moderna Covid 19 Vaccines and her Booster. It was reported after that all of her Autoimmune stuff exploded. The patient feels the Booster caused a lot of her Autoimmune disorders. After her Booster dose the patient was diagnosed with Rheumatoid Arthritis and Myasthenia Gravis and she can't work and she is disabled. The fall after her Booster was when her whole body fell apart and she got the Autoimmune Disorders, Rheumatoid Arthritis and Myasthenia Gravis. It was reported that the patient had started getting rashes, muscle weakness and her skin was falling apart on her hands and she was diagnosed with Dermatomyositis. Her Dermatologist said that Dermatomyositis can be caused by Enbrel. The patient had stopped taking Enbrel has switched to Xeljanz and everything has gotten better. The patient clarifies that it was not completely gone, but it has improved. The patient just got off Enbrel a month ago, on 07-Apr-2023, so they said to give it more time to heal. The patient stopped the Enbrel and the event Dermatomyositis got better. The patient stated that her Dermatologist said Enbrel could cause Dermatomyositis, but she didn't know that. The reporter stated that the Myasthenia Gravis affects the small tiny muscles, and the Dermatomyositis involves her quads, arms, and shoulders. The seriousness Criteria was Disabling. It was reported that the patient couldn't do her ADLs, brush her hair or lift her arms above her head because of the weakness. She couldn't shampoo or comb her hair, her husband had to help her. Treatment information was not provided.  Company comment: This spontaneous case concerns a 41-year-old female patient with no relevant medical history reported, who experienced the unexpected serious (disability and medically significant) events of Dermatomyositis, Rheumatoid arthritis (AESI) and Myasthenia gravis (AESI) after receiving a dose of mRNA-1273 vaccine. Latency unknown as the onset dates of Rheumatoid arthritis and Myasthenia gravis were not specified. It was reported that the patient feels the auto Immune disorders of Myasthenia Gravis and Rheumatoid Arthritis happened after she got a booster dose of mRNA-1273 vaccine. First and second doses of mRNA-1273 vaccine were also administered in appropriate schedule of vaccination. Approximately one year after vaccine was given patient started getting rashes, muscle weakness and her skin fell apart on her hands and was diagnosed with Dermatomyositis. Her Dermatologist said that Dermatomyositis can be caused by etanercept (given for Rheumatoid arthritis, reported as co-suspect). It was reported that she can't work, and she is disabled and couldn't do her activities of daily living (brush her hair or lift her arms above her head because of the weakness, couldn't shampoo or comb her hair, her husband had to help her). Patient´s age and gender remain as possible risk factors; treatment with etanercept remains as a confounder for dermatomyositis and events can be related with each other. The benefit-risk relationship of mRNA-1273 vaccine is not affected by this report. Sender's Comments: This spontaneous case concerns a 41-year-old female patient with no relevant medical history reported, who experienced the unexpected serious (disability and medically significant) events of Dermatomyositis, Rheumatoid arthritis (AESI) and Myasthenia gravis (AESI) after receiving a dose of mRNA-1273 vaccine. Latency unknown as the onset dates of Rheumatoid arthritis and Myasthenia gravis were not specified. It was reported that the patient feels the auto Immune disorders of Myasthenia Gravis and Rheumatoid Arthritis happened after she got a booster dose of mRNA-1273 vaccine. First and second doses of mRNA-1273 vaccine were also administered in appropriate schedule of vaccination. Approximately one year after vaccine was given patient started getting rashes, muscle weakness and her skin fell apart on her hands and was diagnosed with Dermatomyositis. Her Dermatologist said that Dermatomyositis can be caused by etanercept (given for Rheumatoid arthritis, reported as co-suspect). It was reported that she can't work, and she is disabled and couldn't do her activities of daily living (brush her hair or lift her arms above her head because of the weakness, couldn't shampoo or comb her hair, her husband had to help her). Patient´s age and gender remain as possible risk factors; treatment with etanercept remains as a confounder for dermatomyositis and events can be related with each other. The benefit-risk relationship of mRNA-1273 vaccine is not affected by this report.