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 elderly female patient who received mRNA-1273 (Moderna COVID-19 Vaccine) for COVID-19 vaccination.  Co-suspect product included non-company product UPADACITINIB (RINVOQ) for Rheumatoid arthritis.  No Medical History information was reported.  On 20-Mar-2021, the patient received first dose of mRNA-1273 (Moderna COVID-19 Vaccine) (Intramuscular) 1 dosage form. On 18-Apr-2021, received second dose of mRNA-1273 (Moderna COVID-19 Vaccine) (Intramuscular) dosage was changed to 1 dosage form. In 2021, received third dose of mRNA-1273 (Moderna COVID-19 Vaccine) (Intramuscular) dosage was changed to 1 dosage form. On 13-Nov-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 UPADACITINIB (RINVOQ) (Oral) 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 with sequelae.     No concomitant medications were reported. In 2021, patient received 1st booster dose of Moderna COVID-19 Vaccine. On 13-Nov-2021, received 2nd booster dose of Moderna COVID-19 Vaccine. It was unknown if patient was enrolled in a COVID-19 Vaccine Trial. Causality of RINVOQ as per reporter for event Rheumatoid arthritis was reasonable possibility. 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 concerns an elderly female patient, in treatment with co  suspect product Upadacitinib for Rheumatoid arthritis (unknown onset), who received four doses of mRNA-1273 vaccine and experienced the serious medically significant unexpected AESI of Rheumatoid arthritis (described as "Rheumatoid arthritis flare up"). Onset date of the event was not provided, hence latency and temporal association cannot be properly assessed. The outcome was recovered with unspecified sequelae. No further clinical information has been provided for medical reviewing. Patient´s mentioned Rheumatoid arthritis remains as confounder since flaring of symptoms is part of the natural course of the disease. The benefit  risk relationship of mRNA-1273 vaccine is not affected by this report.  Sender's Comments: This spontaneous case concerns an elderly female patient, in treatment with co  suspect product Upadacitinib for Rheumatoid arthritis (unknown onset), who received four doses of mRNA-1273 vaccine and experienced the serious medically significant unexpected AESI of Rheumatoid arthritis (described as "Rheumatoid arthritis flare up"). Onset date of the event was not provided, hence latency and temporal association cannot be properly assessed. The outcome was recovered with unspecified sequelae. No further clinical information has been provided for medical reviewing. Patient´s mentioned Rheumatoid arthritis remains as confounder since flaring of symptoms is part of the natural course of the disease. The benefit  risk relationship of mRNA-1273 vaccine is not affected by this report.