Rheumatoid arthritis flare up; Tingling; Numbness; Vaccination site pain; Pain in hip; This spontaneous case was reported by a consumer and describes the occurrence of RHEUMATOID ARTHRITIS (Rheumatoid arthritis flare up) in an adult male 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 (MODERATE TO SEVERE).   On 20-Mar-2021, the patient received dose of mRNA-1273 (Moderna COVID-19 Vaccine) (Intramuscular) 1 dosage form. On 20-Apr-2021, received dose of mRNA-1273 (Moderna COVID-19 Vaccine) (Intramuscular) dosage was changed to 1 dosage form. On 01-Oct-2021, received 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), PARAESTHESIA (Tingling), HYPOAESTHESIA (Numbness), VACCINATION SITE PAIN (Vaccination site pain) and ARTHRALGIA (Pain in hip). At the time of the report, RHEUMATOID ARTHRITIS (Rheumatoid arthritis flare up), PARAESTHESIA (Tingling) and VACCINATION SITE PAIN (Vaccination site pain) had not resolved and HYPOAESTHESIA (Numbness) and ARTHRALGIA (Pain in hip) outcome was unknown.            No concomitant medications was reported. The patient experienced occasional pain, tingling, and numbness, hip pain, sore arm from Moderna vaccines and tenderness in left knee. The weather effected patient's condition. No treatment medications was reported.  It was unknown if patient was enrolled in a COVID-19 Vaccine Trial.  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 adult male patient with relevant medical history of Rheumatoid arthritis, who experienced the unexpected, serious  (medically significant) adverse event of special interest Rheumatoid arthritis (reported as Rheumatoid arthritis flare up) on an unknown date in the context of receiving a dose of mRNA-1273 vaccine.  Onset latency could not be determined as the date of event onset was not provided. Patient experienced tenderness in the left knee which could be in association with the event. Outcome was reported as not resolved. Patient received two doses of mRNA-1273 as primary series given 31 days apart. Rheumatoid arthritis is known to result in flares, thus, considered a confounder. The benefit-risk relationship of mRNA-1273 vaccine is not affected by this report.; Sender's Comments: This spontaneous case concerns an adult male patient with relevant medical history of Rheumatoid arthritis, who experienced the unexpected, serious  (medically significant) adverse event of special interest Rheumatoid arthritis (reported as Rheumatoid arthritis flare up) on an unknown date in the context of receiving a dose of mRNA-1273 vaccine.  Onset latency could not be determined as the date of event onset was not provided. Patient experienced tenderness in the left knee which could be in association with the event. Outcome was reported as not resolved. Patient received two doses of mRNA-1273 as primary series given 31 days apart. Rheumatoid arthritis is known to result in flares, thus, considered a confounder. The benefit-risk relationship of mRNA-1273 vaccine is not affected by this report.