Sore arm; Upset stomach; patient received a dose of the Moderna COVID-19 vaccine & a booster dose of the Pfizer/BioNTech COVID-19 vaccine; patient received a dose of the Moderna COVID-19 vaccine & a booster dose of the Pfizer/BioNTech COVID-19 vaccine; 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 44-year-old female patient who received mRNA-1273 (Spikevax) for COVID-19 vaccination. The occurrence of additional non-serious events is detailed below.    Co-suspect products included non-company products ADALIMUMAB (HUMIRA) for Rheumatoid arthritis and TOZINAMERAN (PFIZER BIONTECH COVID-19 VACCINE) for COVID-19 vaccination.    Concurrent medical conditions included Rheumatoid arthritis (Moderate to severe).   On an unknown date, the patient received dose of mRNA-1273 (Spikevax) (Intramuscular) 1 dosage form, ADALIMUMAB (HUMIRA) (Subcutaneous) at an unspecified dose and dose of TOZINAMERAN (PFIZER BIONTECH COVID-19 VACCINE) (Intramuscular) 1 dosage form. In 2022, the patient experienced RHEUMATOID ARTHRITIS (Rheumatoid arthritis flare up) (seriousness criterion medically significant). On an unknown date, the patient experienced PAIN IN EXTREMITY (Sore arm), ABDOMINAL DISCOMFORT (Upset stomach), INTERCHANGE OF VACCINE PRODUCTS (patient received a dose of the Moderna COVID-19 vaccine & a booster dose of the Pfizer/BioNTech COVID-19 vaccine) and COVID-19 IMMUNISATION (patient received a dose of the Moderna COVID-19 vaccine & a booster dose of the Pfizer/BioNTech COVID-19 vaccine). In 2022, RHEUMATOID ARTHRITIS (Rheumatoid arthritis flare up) had resolved. At the time of the report, PAIN IN EXTREMITY (Sore arm) and ABDOMINAL DISCOMFORT (Upset stomach) had resolved and INTERCHANGE OF VACCINE PRODUCTS (patient received a dose of the Moderna COVID-19 vaccine & a booster dose of the Pfizer/BioNTech COVID-19 vaccine) and COVID-19 IMMUNISATION (patient received a dose of the Moderna COVID-19 vaccine & a booster dose of the Pfizer/BioNTech COVID-19 vaccine) outcome was unknown.        The action taken with mRNA-1273 (Spikevax) (Intramuscular) was unknown.    Company comment: This spontaneous case concerns a 44-year-old, female patient with medical history of Moderate-to-severe Rheumatoid Arthritis treated with the co-suspect product Humira (adalimumab) and history of co-suspect administration of a booster dose of the Pfizer/BioNTech COVID-19 mRNA vaccine, who experienced the unexpected, serious (medically significant) AESI of rheumatoid arthritis flare-up and other unexpected, non-serious events. The event rheumatoid arthritis flare-up occurred unknown number of days after receiving Humira, unknown number of days after receiving an unspecified dose of the mRNA-1273 vaccine, and unknown number of days after receiving a booster dose of the Pfizer/BioNTech COVID-19 mRNA vaccine (revaccination with different COVID-19 vaccine and interchange of vaccine products). Of note, the event onset date was reported as unspecified date in 2022 while the administration dates of Humira, mRNA-1273 vaccine and Pfizer/BioNTech COVID-19 mRNA vaccine were not provided, hence, the onset latency could not be assessed. The start dates of the non-serious events pain in extremity and abdominal discomfort were not provided, hence, the onset latency also could not be assessed. On unknown dates, the patient experienced sore arm and an upset stomach. It was also reported that the patient experienced rheumatoid arthritis flare-up. No further details were provided. However, the events had resolved at the time of the report. The medical history of Rheumatoid Arthritis, a chronic inflammatory disorder characterized by flares and remission, remains a confounder for the event rheumatoid arthritis flare-up. The co-suspect administration of Humira and the Pfizer/BioNTech COVID-19 mRNA vaccine remain as confounders for the reported events. The benefit-risk relationship of the mRNA-1273 vaccine is not affected by this report.   No concomitant medications were reported.  In 2022, patient experienced Rheumatoid arthritis flare up and resolved in 2022.  It was unknown if patient was enrolled in a COVID-19 Vaccine trial. No treatment medication was reported.   The reporters causality of Humira for the events Rheumatoid arthritis flare up, sore arm and upset stomach was not provided and that of for Pfizer it was reported to be possible for all events.  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.; Sender's Comments: This spontaneous case concerns a 44-year-old, female patient with medical history of Moderate-to-severe Rheumatoid Arthritis treated with the co-suspect product Humira (adalimumab) and history of co-suspect administration of a booster dose of the Pfizer/BioNTech COVID-19 mRNA vaccine, who experienced the unexpected, serious (medically significant) AESI of rheumatoid arthritis flare-up and other unexpected, non-serious events. The event rheumatoid arthritis flare-up occurred unknown number of days after receiving Humira, unknown number of days after receiving an unspecified dose of the mRNA-1273 vaccine, and unknown number of days after receiving a booster dose of the Pfizer/BioNTech COVID-19 mRNA vaccine (revaccination with different COVID-19 vaccine and interchange of vaccine products). Of note, the event onset date was reported as unspecified date in 2022 while the administration dates of Humira, mRNA-1273 vaccine and Pfizer/BioNTech COVID-19 mRNA vaccine were not provided, hence, the onset latency could not be assessed. The start dates of the non-serious events pain in extremity and abdominal discomfort were not provided, hence, the onset latency also could not be assessed. On unknown dates, the patient experienced sore arm and an upset stomach. It was also reported that the patient experienced rheumatoid arthritis flare-up. No further details were provided. However, the events had resolved at the time of the report. The medical history of Rheumatoid Arthritis, a chronic inflammatory disorder characterized by flares and remission, remains a confounder for the event rheumatoid arthritis flare-up. The co-suspect administration of Humira and the Pfizer/BioNTech COVID-19 mRNA vaccine remain as confounders for the reported events. The benefit-risk relationship of the mRNA-1273 vaccine is not affected by this report.