Rheumatoid arthritis flare up; Pain and mobility issues in left arm/sore arm from moderna vacine booster shot; Vaccination site pain/ PAIN ISSUES IN LEFT ARM; This spontaneous case was reported by a consumer and describes the occurrence of RHEUMATOID ARTHRITIS (Rheumatoid arthritis flare up) in a 71-year-old female 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 ADALIMUMAB (HUMIRA) for Rheumatoid arthritis.    Concurrent medical conditions included Rheumatoid arthritis.   On 09-Feb-2021, the patient received first dose of mRNA-1273 (Moderna COVID-19 Vaccine) (Intramuscular) 1 dosage form. On 09-Mar-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 an unknown date, the patient started ADALIMUMAB (HUMIRA) (Subcutaneous) Citrate free. In 2021, the patient experienced VACCINATION SITE MOVEMENT IMPAIRMENT (Pain and mobility issues in left arm/sore arm from moderna vacine booster shot) and VACCINATION SITE PAIN (Vaccination site pain/ PAIN ISSUES IN LEFT ARM). 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), VACCINATION SITE MOVEMENT IMPAIRMENT (Pain and mobility issues in left arm/sore arm from moderna vacine booster shot) and VACCINATION SITE PAIN (Vaccination site pain/ PAIN ISSUES IN LEFT ARM) had not resolved.            Concomitant products were not provided. Treatment medication were not reported.  This case was identified as part of a retrospective clean-up activity received in the Moderna  were missed to be booked-in.  It was unknown if patient was enrolled in a COVID-19 Vaccine Trial.  The reporter's causality for the event(s) of PAIN AND MOBILITY ISSUES IN LEFT ARM/SORE ARM FROM MODERNA VACINE BOOSTER SHOT onset in 2021 and PAIN AND MOBILITY ISSUES IN LEFT ARM/SORE ARM FROM MODERNA VACINE BOOSTER SHOT onset in 2021 with HUMIRA(ADALIMUMAB) was no reasonable possibility. The reporter's causality for the event(s) of RHEUMATOID ARTHRITIS FLARE UP with HUMIRA(ADALIMUMAB) was a reasonable possibility.  Company Comment:  This spontaneous case concerns a 71-year-old female patient with concurrent Rheumatoid arthritis, who experienced the unexpected, serious  (medically significant) adverse event of special interest Rheumatoid arthritis (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 date of event onset was not provided. Adalimumab treatment was reported as ongoing.  A 2-dose primary series of mRNA-1273 vaccine was given 28 days apart. The concurrent Rheumatoid arthritis remains a confounder as the disease itself is known to result in flares. The benefit-risk relationship of mRNA-1273 vaccine is not affected by this report.; Sender's Comments: This spontaneous case concerns a 71-year-old female patient with concurrent Rheumatoid arthritis, who experienced the unexpected, serious  (medically significant) adverse event of special interest Rheumatoid arthritis (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 date of event onset was not provided. Adalimumab treatment was reported as ongoing.  A 2-dose primary series of mRNA-1273 vaccine was given 28 days apart. The concurrent Rheumatoid arthritis remains a confounder as the disease itself is known to result in flares. The benefit-risk relationship of mRNA-1273 vaccine is not affected by this report.