Autoimmune disease flare-up/very bad flares after both of my covid vaccines; This spontaneous case was reported by an other health care professional and describes the occurrence of AUTOIMMUNE DISORDER (Autoimmune disease flare-up/very bad flares after both of my covid vaccines) in a  patient of an unknown age and gender who received mRNA-1273 (Spikevax) for COVID-19 prophylaxis.     Concurrent medical conditions included Autoimmune disorder NOS (had symptoms of my autoimmune disease since I was a teen).    On an unknown date, the patient received first dose of mRNA-1273 (Spikevax) (unknown route) 1 dosage form. On an unknown date, the patient experienced AUTOIMMUNE DISORDER (Autoimmune disease flare-up/very bad flares after both of my covid vaccines) (seriousness criterion medically significant). At the time of the report, AUTOIMMUNE DISORDER (Autoimmune disease flare-up/very bad flares after both of my covid vaccines) outcome was unknown.        mRNA-1273 (Spikevax) (Unknown) dosing remained unchanged.   For mRNA-1273 (Spikevax) (Unknown), the reporter did not provide any causality assessments.   No concomitant medication information was  provided.  It was reported that the vaccine had an adjuvant in it. Adjuvants literally stimulate the immune system to encourage antibody production. They work great for healthy people. They ramp up the disease causing immune system for people with an autoimmune disease.  It was mentioned that It's unlikely that the covid vaccine causes anyone to develop any autoimmune disease. It was much more likely that the vaccine stimulates people's immune systems enough that it causes preexisting autoimmune diseases to flare to a level they've never reached before.  Patient had symptoms of autoimmune disease since patient was a teen. Most vaccines were no problem for patient but had very bad flares after both of covid vaccines. Patient thought that  they used a stronger adjuvant (at least in the Moderna vaccine) than most other vaccines contain.  No treatment medication information was provided.  Company Comment: This is a spontaneous case concerning a patient of an unknown age and gender with medical history of Autoimmune Disorder, who experienced the unexpected, serious, event of Autoimmune disorder which was medically significant and occurred on an unknown date after receiving the first dose of mRNA-1273 Vaccine. No further information on clinical course and management of the event was available in the report. It was reported that the outcome of the events was unknown. The medical history of Autoimmune Disorder remains a confounder. The benefit-risk relationship of mRNA-1273 Vaccine is not affected by this report.   This case was linked to MOD-2022-589263 (Patient Link).; Sender's Comments: This is a spontaneous case concerning a patient of an unknown age and gender with medical history of Autoimmune Disorder, who experienced the unexpected, serious, event of Autoimmune disorder which was medically significant and occurred on an unknown date after receiving the first dose of mRNA-1273 Vaccine. No further information on clinical course and management of the event was available in the report. It was reported that the outcome of the events was unknown. The medical history of Autoimmune Disorder remains a confounder. The benefit-risk relationship of mRNA-1273 Vaccine is not affected by this report.