Rheumatoid arthritis flare up; This spontaneous case was reported by a consumer and describes the occurrence of RHEUMATOID ARTHRITIS (Rheumatoid arthritis flare up) in a 57-year-old female patient who received mRNA-1273 (Moderna COVID-19 Vaccine) for COVID-19 vaccination.    Co-suspect product included non-company product ADALIMUMAB (HUMIRA) solution for injection for Rheumatoid arthritis.    No Medical History information was reported.   On 19-Mar-2021, the patient received first dose of mRNA-1273 (Moderna COVID-19 Vaccine) (Intramuscular) 1 dosage form. On 16-Apr-2021, received second dose of mRNA-1273 (Moderna COVID-19 Vaccine) (Intramuscular) dosage was changed to 1 dosage form. On 27-Aug-2021, received third dose of mRNA-1273 (Moderna COVID-19 Vaccine) (Intramuscular) dosage was changed to 1 dosage form. On an unknown date, the patient started ADALIMUMAB (HUMIRA) (Subcutaneous) at an unspecified dose. In 2021, the patient experienced RHEUMATOID ARTHRITIS (Rheumatoid arthritis flare up) (seriousness criterion medically significant). In 2021, RHEUMATOID ARTHRITIS (Rheumatoid arthritis flare up) had resolved.            No Concomitant medications were reported. No treatment medications were reported.  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 spontaneous case reported by a consumer, concerns a 57 year old female patient, with no relevant medical history reported, who experienced the unexpected, serious, (medically significant) AESI of Rheumatoid arthritis (Rheumatoid arthritis flare up) in the same year, but unknown days after receiving the 3 dose of mRNA-1273 vaccine in the covid 19 vaccination series. Patient previously received the two primary doses with Moderna vaccines about 4 months prior to the 3 dose, with no adverse events reported. On an unknown date, the patient had received ADALIMUMAB for Rheumatoid Arthritis, which could be considered as a confounder to the flare up of Rheumatoid Arthritis. No further clinical information on comorbidities, risk factors, labs, diagnostics, concomitant medications and treatment details were reported. The event had resolved. The benefit-risk relationship of mRNA- 1273 vaccine is not affected by this report.; Sender's Comments: This spontaneous case reported by a consumer, concerns a 57 year old female patient, with no relevant medical history reported, who experienced the unexpected, serious, (medically significant) AESI of Rheumatoid arthritis (Rheumatoid arthritis flare up) in the same year, but unknown days after receiving the 3 dose of mRNA-1273 vaccine in the covid 19 vaccination series. Patient previously received the two primary doses with Moderna vaccines about 4 months prior to the 3 dose, with no adverse events reported. On an unknown date, the patient had received ADALIMUMAB for Rheumatoid Arthritis, which could be considered as a confounder to the flare up of Rheumatoid Arthritis. No further clinical information on comorbidities, risk factors, labs, diagnostics, concomitant medications and treatment details were reported. The event had resolved. The benefit-risk relationship of mRNA- 1273 vaccine is not affected by this report.