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 65-year-old 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.    Concurrent medical conditions included Rheumatoid arthritis.   On 14-Oct-2019, the patient started UPADACITINIB (RINVOQ) (Oral) 1 dosage form. In March 2021, the patient received first dose of mRNA-1273 (Moderna COVID-19 Vaccine) (Intramuscular) 1 dosage form. In April 2021, received second dose of mRNA-1273 (Moderna COVID-19 Vaccine) (Intramuscular) dosage was changed to 1 dosage form. In November 2021, received third dose of mRNA-1273 (Moderna COVID-19 Vaccine) (Intramuscular) dosage was changed to 1 dosage form. In November 2021, the patient experienced RHEUMATOID ARTHRITIS (Rheumatoid arthritis flare up). At the time of the report, RHEUMATOID ARTHRITIS (Rheumatoid arthritis flare up) outcome was unknown.            Concomitant product use was not provided by the reporter. the patient reported having a flare up of rheumatoid arthritis post her first booster dose of the vaccine. The reporter causality for event of rheumatoid arthritis flare up for Rinvoq was provided as no reasonable possibility. Treatment information was not provided.  This spontaneous case concerns a 65-year-old, female patient with relevant current condition of Rheumatoid arthritis maintained on Upadacitinib who experienced the unexpected, non-serious adverse event of special interest of Rheumatoid arthritis (reported as Rheumatoid arthritis flare up) which occurred on the same month of administration of third dose of mRNA-1273 vaccine taken as first booster dose of COVID-19 immunization. Patient also received mRNA-1273 for the primary series of COVID-19 vaccination with the last dose taken approximately 7 months prior to the first booster dose. Patient stated that she felt having a flare up but not concerned as she felt similar after receiving the previous dose of vaccine. The clinical presentation was not reported in this case. Rheumatoid arthritis can flare as part of the natural history of disease. Underlying disease severity remains a confounder for the event. The benefit-risk relationship of mRNA-1273 is not affected by this report.   This case was linked to MOD-2022-568033, MOD-2022-568997 (Patient Link).; Sender's Comments: This spontaneous case concerns a 65-year-old, female patient with relevant current condition of Rheumatoid arthritis maintained on Upadacitinib who experienced the unexpected, non-serious adverse event of special interest of Rheumatoid arthritis (reported as Rheumatoid arthritis flare up) which occurred on the same month of administration of third dose of mRNA-1273 vaccine taken as first booster dose of COVID-19 immunization. Patient also received mRNA-1273 for the primary series of COVID-19 vaccination with the last dose taken approximately 7 months prior to the first booster dose. Patient stated that she felt having a flare up but not concerned as she felt similar after receiving the previous dose of vaccine. The clinical presentation was not reported in this case. Rheumatoid arthritis can flare as part of the natural history of disease. Underlying disease severity remains a confounder for the event. The benefit-risk relationship of mRNA-1273 is not affected by this report.