Rheumatoid arthritis flare up; Flu like symptoms; Headache; This spontaneous case was reported by a consumer and describes the occurrence of RHEUMATOID ARTHRITIS (Rheumatoid arthritis flare up) in a 51-year-old female patient who received mRNA-1273 (Moderna COVID-19 Vaccine) for COVID-19 vaccination. The occurrence of additional non-serious events is detailed below.    Co-suspect product included non-company product UPADACITINIB (RINVOQ) for Rheumatoid arthritis.    Concurrent medical conditions included Rheumatoid arthritis.   On 09-Mar-2021, the patient received first dose of mRNA-1273 (Moderna COVID-19 Vaccine) (Intramuscular) 1 dosage form. On 09-Apr-2021, received second dose of mRNA-1273 (Moderna COVID-19 Vaccine) (Intramuscular) dosage was changed to 1 dosage form. On an unknown date, the patient started UPADACITINIB (RINVOQ) (Oral) at an unspecified dose. On 09-Apr-2021, the patient experienced INFLUENZA LIKE ILLNESS (Flu like symptoms) and HEADACHE (Headache). On 21-Oct-2021, the patient experienced RHEUMATOID ARTHRITIS (Rheumatoid arthritis flare up) (seriousness criterion medically significant). At the time of the report, RHEUMATOID ARTHRITIS (Rheumatoid arthritis flare up), INFLUENZA LIKE ILLNESS (Flu like symptoms) and HEADACHE (Headache) outcome was unknown.            No concomitant medication provided. No treatment information mentioned.  Patient initially got a headache with first COVID vaccine. Then on 09APR2021, got a headache and flu like symptoms. On 21OCT2021, had a rheumatoid arthritis flare up.  This case was identified as part of a retrospective clean-up activity where certain emails received in the Moderna mailbox were missed to be booked-in  Company Comment: This is a Spontaneous case reported by a consumer, concerning a 51-year-oldl female patient, with relevant medical condition of rheumatoid arthritis, who experienced the unexpected and serious (due to medically significant) AESI of Rheumatoid arthritis (reported as rheumatoid arthritis flare up), which occurred approximately 6 months and a half after second dose of mRNA-1273 vaccine. Co-suspect product includes non-company product Upadacitinib for rheumatoid arthritis. No information disclosed about diagnostic tests performed, clinical course or treatments received. Rheumatoid arthritis can present relapses as part of the natural history of disease, so that confounds the case. The benefit-risk relationship of mRNA-1273 vaccine, is not affected by this report.   This case was linked to MOD-2021-619941 (Patient Link).; Sender's Comments: This is a Spontaneous case reported by a consumer, concerning a 51-year-oldl female patient, with relevant medical condition of rheumatoid arthritis, who experienced the unexpected and serious (due to medically significant) AESI of Rheumatoid arthritis (reported as rheumatoid arthritis flare up), which occurred approximately 6 months and a half after second dose of mRNA-1273 vaccine. Co-suspect product includes non-company product Upadacitinib for rheumatoid arthritis. No information disclosed about diagnostic tests performed, clinical course or treatments received. Rheumatoid arthritis can present relapses as part of the natural history of disease, so that confounds the case. The benefit-risk relationship of mRNA-1273 vaccine, is not affected by this report.