Rheumatoid arthritis flare up; Booster day after felt sick; Intense hand pain; This spontaneous case was reported by a consumer and describes the occurrence of RHEUMATOID ARTHRITIS (Rheumatoid arthritis flare up) in an adult 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) solution for injection for Rheumatoid arthritis.    Concurrent medical conditions included Rheumatoid arthritis (Moderate to severe).   On an unknown date, the patient received dose of mRNA-1273 (Moderna COVID-19 Vaccine) (Intramuscular) 1 dosage form On an unknown date, received first dose of mRNA-1273 (Moderna COVID-19 Vaccine) (Intramuscular) dosage was changed to 1 dosage form. and ADALIMUMAB (HUMIRA) (Subcutaneous) at an unspecified dose. On an unknown date, the patient experienced RHEUMATOID ARTHRITIS (Rheumatoid arthritis flare up) (seriousness criterion medically significant), IMMUNISATION REACTION (Booster day after felt sick) and VACCINATION SITE PAIN (Intense hand pain). At the time of the report, RHEUMATOID ARTHRITIS (Rheumatoid arthritis flare up), IMMUNISATION REACTION (Booster day after felt sick) and VACCINATION SITE PAIN (Intense hand pain) had resolved.        The action taken with mRNA-1273 (Moderna COVID-19 Vaccine) (Intramuscular) was unknown.       No concomitant medications were reported.  It was reported that, the patient felt sick and intense hand pain, rheumatoid arthritis flare up in hands and bad pain.  Causality for Humira(adalimumab): The reporter's causality for the event(s) of booster day after felt sick and intense hand pain unknown onset, booster day after felt sick and intense hand pain unknown onset and rheumatoid arthritis flare up in hands with Humira(adalimumab) was no reasonable possibility. the reporter's causality for the event(s) of bad pain was not provided.  The formulation for Humira was reported as Solution for injection in pre-filled pen.  It was unknown if patient was enrolled in a COVID-19 Vaccine Trial.  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 adult female 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 the booster dose of mRNA-1273 vaccine.  Onset latency could not be determined as the vaccination date and onset date of event  were not disclosed. Patient was treated with Adalimumab (Humira).  No information on any other doses of COVID-19 vaccination was provided. The relevant medical history of 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 an adult female 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 the booster dose of mRNA-1273 vaccine.  Onset latency could not be determined as the vaccination date and onset date of event  were not disclosed. Patient was treated with Adalimumab (Humira).  No information on any other doses of COVID-19 vaccination was provided. The relevant medical history of 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.