RHEUMATOID ARTHRITIS FLARE UP; This spontaneous case was reported by a consumer and describes the occurrence of RHEUMATOID ARTHRITIS (RHEUMATOID ARTHRITIS FLARE UP) in an adult female patient who received mRNA-1273 (Moderna COVID-19 Vaccine) for COVID-19 vaccination.    Co-suspect product included non-company product ADALIMUMAB (HUMIRA) for Rheumatoid arthritis.    There was no reported medical history.  Concurrent medical conditions included Rheumatoid arthritis. Concomitant products included METHOTREXATE for an unknown indication.   On an unknown date, the patient received third dose of mRNA-1273 (Moderna COVID-19 Vaccine) (Intramuscular) 1 dosage form On an unknown date, received second dose of mRNA-1273 (Moderna COVID-19 Vaccine) (Intramuscular) dosage was changed to 1 dosage form and first dose of mRNA-1273 (Moderna COVID-19 Vaccine) (Intramuscular) dosage was changed to 1 dosage form. and ADALIMUMAB (HUMIRA) (Subcutaneous) at an unspecified dose. On an unknown date, 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) had resolved.            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  It was unknown if patient was enrolled in a covid-19 vaccine trial. Treatment medications were not reported.  The reporter's causality for the event(s) of rheumatoid arthritis flare up with Humira(adalimumab) was no reasonable possibility. Company comment: This spontaneous case concerns an adult female patient of an unknown age, with concurrent medical history of rheumatoid arthritis treated with co-suspect Adalimumab, with concomitant Methotrexate, who experienced the unexpected serious (medically significant) AESI Rheumatoid arthritis (reported as rheumatoid arthritis flare up) after receiving a dose of mRNA-1273 vaccine. Latency cannot be assessed as the vaccination date and onset date of the event was not provided. Patient received 3 doses of mRNA-1273 vaccine, dates were not provided. Clinical course and treatment details were not reported. The outcome of event was reported as resolved. Concurrent rheumatoid arthritis and Adalimumab could be confounders.  The benefit-risk relationship of mRNA-1273 is not affected by this report.; Sender's Comments: This spontaneous case concerns an adult female patient of an unknown age, with concurrent medical history of rheumatoid arthritis treated with co-suspect Adalimumab, with concomitant Methotrexate, who experienced the unexpected serious (medically significant) AESI Rheumatoid arthritis (reported as rheumatoid arthritis flare up) after receiving a dose of mRNA-1273 vaccine. Latency cannot be assessed as the vaccination date and onset date of the event was not provided. Patient received 3 doses of mRNA-1273 vaccine, dates were not provided. Clinical course and treatment details were not reported. The outcome of event was reported as resolved. Concurrent rheumatoid arthritis and Adalimumab could be confounders.  The benefit-risk relationship of mRNA-1273 is not affected by this report.