Sero positive active inflammatory rheumatoid arthritis and spread to all of her joints/Constant Flu like symptoms; Shortness of breath; Brain fog; This spontaneous case was reported by a patient family member or friend and describes the occurrence of RHEUMATOID ARTHRITIS (Sero positive active inflammatory rheumatoid arthritis and spread to all of her joints/Constant Flu like symptoms) in a female patient of an unknown age who received mRNA-1273 (Moderna COVID-19 Vaccine) for COVID-19 prophylaxis. The occurrence of additional non-serious events is detailed below.     No Medical History information was reported.    On 05-Sep-2021, the patient received second dose of mRNA-1273 (Moderna COVID-19 Vaccine) (unknown route) 1 dosage form. On an unknown date, the patient experienced RHEUMATOID ARTHRITIS (Sero positive active inflammatory rheumatoid arthritis and spread to all of her joints/Constant Flu like symptoms) (seriousness criterion medically significant), DYSPNOEA (Shortness of breath) and BRAIN FOG (Brain fog). At the time of the report, RHEUMATOID ARTHRITIS (Sero positive active inflammatory rheumatoid arthritis and spread to all of her joints/Constant Flu like symptoms) had not resolved and DYSPNOEA (Shortness of breath) and BRAIN FOG (Brain fog) outcome was unknown.      DIAGNOSTIC RESULTS (normal ranges are provided in parenthesis if available): On an unknown date, Blood test: Showed high CCP. On an unknown date, C-reactive protein: High. On an unknown date, Magnetic resonance imaging: severe joint erosion in hands and wrists and deformities in the hands due to chronic inflammation.. On an unknown date, Red blood cell sedimentation rate: High.         No relevant concomitant medications were reported.   Patient's father reported that that within a few weeks of second Moderna Covid 19 vaccine her daughter started having side effects from it - extreme fatigue and flu like symptoms, within a couple of days extreme swelling in her fingers and feet started where she could not walk or use her hands. This progressed extremely fast over 10 weeks which has now been diagnosed as sero positive active inflammatory rheumatoid arthritis and spread to all her joints.  Patient was currently having to return to live with her mother and she struggled to manage independently.  For the past three months patient was having severe swollen veins in arms and hands and was undergoing diagnosis to the cause of this. Other symptoms she has experienced with this illness is extreme fatigue and weakness, shortness of breath, brain fog and constant flu like symptoms.  patient has been told this was an incurable autoimmune disease, she had been 100% fit and well her entire life and used to exercise regularly, 3 times a week at a private gym, until the covid19 vaccine triggered her antibodies to go faulty. There was no genetic connection of this illness in her family. she has been unwell immediately after her second vaccine. After speaking and private doctors they understood that it was the spike protein that was causing patient's own antibodies to attach her. While the doctors were trying to manage patient's condition with lots of different types of drugs, none of them were working and her condition was worsening.  Company Comment: This spontaneous case concerns a female patient of unknown age with no medical history reported, who experienced the unexpected serious (medically significant) AESI Rheumatoid Arthritis within a few weeks after receiving a dose of mRNA-1273 vaccine, given as a second dose of COVID vaccine schedule. It was reported that patient started having extreme fatigue and flu like symptoms, and within a couple of days extreme swelling in her fingers and feet, she could not walk or use her hands. This progressed extremely fast over 10 weeks and was diagnosed with seropositive active inflammatory rheumatoid arthritis that spread to all her joints.  Patient was currently having to return to live with her mother and she struggled to manage independently.  Other symptoms she has experienced with this illness is extreme fatigue and weakness, shortness of breath, brain fog and constant flu like symptoms.  Patient has been told this was an incurable autoimmune disease, she had been 100% fit and well her entire life and used to exercise regularly, 3 times a week. Doctors are trying to manage patient's condition with lots of different types of drugs, none of them are working and her condition is worsening. Patient´s gender remains as a possible risk factor for rheumatoid arthritis. The benefit-risk relationship of mRNA-1273 vaccine is not affected by this report.; Sender's Comments: This spontaneous case concerns a female patient of unknown age with no medical history reported, who experienced the unexpected serious (medically significant) AESI Rheumatoid Arthritis within a few weeks after receiving a dose of mRNA-1273 vaccine, given as a second dose of COVID vaccine schedule. It was reported that patient started having extreme fatigue and flu like symptoms, and within a couple of days extreme swelling in her fingers and feet, she could not walk or use her hands. This progressed extremely fast over 10 weeks and was diagnosed with seropositive active inflammatory rheumatoid arthritis that spread to all her joints.  Patient was currently having to return to live with her mother and she struggled to manage independently.  Other symptoms she has experienced with this illness is extreme fatigue and weakness, shortness of breath, brain fog and constant flu like symptoms.  Patient has been told this was an incurable autoimmune disease, she had been 100% fit and well her entire life and used to exercise regularly, 3 times a week. Doctors are trying to manage patient's condition with lots of different types of drugs, none of them are working and her condition is worsening. Patient´s gender remains as a possible risk factor for rheumatoid arthritis. The benefit-risk relationship of mRNA-1273 vaccine is not affected by this report.