Anti-MDA5 antibody-positive dermatomyositis; Anti-MDA5 antibody-positive dermatomyositis; Rapidly progressive interstitial lung disease; This literature case from the country was received from other healthcare professional on 09-Oct-2023 and concerned a 61-year-old, female patient.   The aim of this conference abstract was to report a case of Antimelanoma differentiation-associated gene 5-positive dermatomyositis (Anti-MDA5 ab DM) with associated rapidly progressive interstitial lung disease (RP-ILD) after COVID and influenza vaccination  The patient's concurrent conditions included hypothyroidism and untreated latent tuberculosis (TB). The patient's concomitant medications were not reported.  On an unspecified date, the patient was vaccinated with influenza vaccine (brand not specified; dose, route of administration, anatomical location, and indication: not reported). The batch number was not reported.   On the same date, the patient was vaccinated with non-company co-suspect COVID-19 vaccine (brand not specified; dose, route of administration, anatomical location, and indication: not reported). The batch number was not reported.   On an unspecified date, shortly after receiving influenza vaccine and non-company co-suspect COVID-19 vaccine, the patient experienced progressive shortness of breath, polyarticular joint pain, weight loss, and malaise which caused the patient being assessed on an outpatient basis four times within a two-month period. The patient was referred to rheumatology and treated with short courses of prednisone for inflammatory arthritis.   On an unspecified date, the patient was presented to the emergency department due to symptoms progression to acute hypoxic respiratory failure which required a high-flow nasal cannula. The initial workshop was notable for severely elevated erythrocyte sedimentation rate (ESR) and C-reactive protein (CRP), elevated partial thromboplastin time (PTT), and aspartate aminotransferase (AST), a normal white count with decreased lymphocytes and one plus protein on urinalysis (UA). In addition, chest imaging was performed and revealed extensive multifocal ground glass opacities. Within 24 hours the patient required intubation and was transfer to the intensive care unit. Furthermore, bronchoalveolar lavage was notable for a positive Pneumocystis jirovecii polymerase chain reaction (PCR) for which patient was treated with trimethoprim/sulfamethoxazole (TMP/SMX) and methylprednisolone.   On an unspecified date, on day six of hospitalization, the patient was initiated on venovenous (VV) extracorporeal membrane oxygenation (ECMO).   On an unspecified date, reported as later, Rheumatologic workup revealed positive anti-MDA5 ab. Immunotherapy was initiated with high dose prednisone and then cyclophosphamide following treatment for Pneumocystis pneumonia (PJP). This patient with rapidly progressive interstitial lung disease due to Anti-MDA5 antibody-positive dermatomyositis was initially difficult to diagnose due to concern for other causes of acute respiratory failure, in particular, PJP. It was reported that the patient, never experienced meaningful recovery of pulmonary function and as the patient was not a candidate for lung transplant.   On an unspecified date, on hospital day 51, the patient succumbed to illness. The information regarding autopsy performed was not provided. The cause of death was rapidly progressive interstitial lung disease due to Anti-MDA5 antibody-positive dermatomyositis.   The reporter did not provide a causality assessment. It was reported that prior small studies have shown increased incidence of myositis-related anti-RNA-synthetases auto-antibodies after administration of COVID mRNA vaccine. The reporters suspicion was that this patient developed anti-MDA5 ab as a result of her COVID mRNA vaccination and subsequent development of RP-ILD was secondary to her anti-MDA5 DM.  The events were considered to be serious due to seriousness criterion of hospitalization, and  fatal outcome.  In conclusion, this case underscores the importance of recognizing the rare od dermatomyositis, particularly considering the increased production of autoantibodies following widespread COVID vaccination. Despite this rare and catastrophic outcome, the benefits of COVID vaccination remain at the forefront of population health. Early recognition of the severe complication of RP-ILD may help with diagnosis and early initiation of directed therapies.      Company comment: A 61-year-old patient with medical history of hypothyroidism and untreated latent tuberculosis, was vaccinated with influenza vaccine and non-company co-suspect COVID-19 vaccine. On an unspecified date, shortly after vaccination, the patient experienced progressive shortness of breath, polyarticular joint pain, weight loss, and malaise. The patient was referred to rheumatology and treated with short courses of prednisone for inflammatory arthritis. On an unspecified date, the patient was presented to the emergency department due to symptoms progression to acute hypoxic respiratory failure. Within 24 hours the patient required intubation and was transfer to the intensive care unit. Furthermore, bronchoalveolar lavage was notable for a positive Pneumocystis jirovecii polymerase chain reaction (PCR) for which patient was treated with trimethoprim/sulfamethoxazole (TMP/SMX) and methylprednisolone. Afterwards, rheumatologic workup revealed positive anti-MDA5 ab. This patient with rapidly progressive interstitial lung disease due to Anti-MDA5 antibody-positive dermatomyositis was initially difficult to diagnose due to concern for other causes of acute respiratory failure, in particular, PJP. On an unspecified date, the patient succumbed to illness. The cause of death was rapidly progressive interstitial lung disease due to Anti-MDA5 antibody-positive dermatomyositis. It was reported that prior small studies have shown increased incidence of myositis-related anti-RNA-synthetases auto-antibodies after administration of COVID mRNA vaccine. Therefore, causality was highly confounded by co-suspect vaccine, however, causal role of influenza vaccine cannot be excluded. With information available, causal role of influenza vaccine is assessed as unlikely for the events of Anti-MDA5 antibody-positive dermatomyositis and Interstitial lung disease. (defaults to "Related" in the safety database); Reporter's Comments: It was reported that prior small studies have shown increased incidence of myositis-related anti-RNA-synthetases auto-antibodies after administration of COVID mRNA vaccine. The reporters suspicion was that this patient developed anti-MDA5 ab as a result of her COVID mRNA vaccination and subsequent development of RP-ILD was secondary to her anti-MDA5 DM.; Sender's Comments: A 61-year-old patient with medical history of hypothyroidism and untreated latent tuberculosis, was vaccinated with influenza vaccine and non-company co-suspect COVID-19 vaccine. On an unspecified date, shortly after vaccination, the patient experienced progressive shortness of breath, polyarticular joint pain, weight loss, and malaise. The patient was referred to rheumatology and treated with short courses of prednisone for inflammatory arthritis. On an unspecified date, the patient was presented to the emergency department due to symptoms progression to acute hypoxic respiratory failure. Within 24 hours the patient required intubation and was transfer to the intensive care unit. Furthermore, bronchoalveolar lavage was notable for a positive Pneumocystis jirovecii polymerase chain reaction (PCR) for which patient was treated with trimethoprim/sulfamethoxazole (TMP/SMX) and methylprednisolone. Afterwards, rheumatologic workup revealed positive anti-MDA5 ab. This patient with rapidly progressive interstitial lung disease due to Anti-MDA5 antibody-positive dermatomyositis was initially difficult to diagnose due to concern for other causes of acute respiratory failure, in particular, PJP. On an unspecified date, the patient succumbed to illness. The cause of death was rapidly progressive interstitial lung disease due to Anti-MDA5 antibody-positive dermatomyositis. It was reported that prior small studies have shown increased incidence of myositis-related anti-RNA-synthetases auto-antibodies after administration of COVID mRNA vaccine. Therefore, causality was highly confounded by co-suspect vaccine, however, causal role of influenza vaccine cannot be excluded. With information available, causal role of influenza vaccine is assessed as unlikely for the events of Anti-MDA5 antibody-positive dermatomyositis and Interstitial lung disease. (defaults to "Related" in the safety database); Reported Cause(s) of Death: Anti-MDA5 antibody-positive dermatomyositis; Anti-MDA5 antibody-positive dermatomyositis; Rapidly progressive interstitial lung disease