Numbness in feet; Tingling of extremity; Muscle pain; Rheumatoid arthritis flare up; Muscle tightness; Patient received 1st and 2nd doses of mRNA-1273 vaccine 6 months apart; Felt ill; This spontaneous case was reported by a consumer and describes the occurrence of RHEUMATOID ARTHRITIS (Rheumatoid arthritis flare up) in a 78-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.    No Medical History information was reported.   On 21-Apr-2021, the patient received first dose of mRNA-1273 (Moderna COVID-19 Vaccine) (Intramuscular) 1 dosage form. On 20-Oct-2021, received second 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 MALAISE (Felt ill). On 20-Oct-2021, the patient experienced INAPPROPRIATE SCHEDULE OF PRODUCT ADMINISTRATION (Patient received 1st and 2nd doses of mRNA-1273 vaccine 6 months apart). On 06-May-2022, the patient experienced MUSCLE TIGHTNESS (Muscle tightness). On an unknown date, the patient experienced RHEUMATOID ARTHRITIS (Rheumatoid arthritis flare up) (seriousness criterion medically significant), HYPOAESTHESIA (Numbness in feet), PARAESTHESIA (Tingling of extremity) and MYALGIA (Muscle pain). The patient was treated with MELOXICAM at an unspecified dose and frequency. At the time of the report, RHEUMATOID ARTHRITIS (Rheumatoid arthritis flare up), HYPOAESTHESIA (Numbness in feet) and MYALGIA (Muscle pain) had not resolved and MALAISE (Felt ill), MUSCLE TIGHTNESS (Muscle tightness), PARAESTHESIA (Tingling of extremity) and INAPPROPRIATE SCHEDULE OF PRODUCT ADMINISTRATION (Patient received 1st and 2nd doses of mRNA-1273 vaccine 6 months apart) outcome was unknown.      DIAGNOSTIC RESULTS (normal ranges are provided in parenthesis if available): On an unknown date, Red blood cell sedimentation rate: Increased high 79. On an unknown date, Weight: decreased 47.6272 KG.         No concomitant medications was reported. Unknown date HIGH SEDIMENT RATE: high 79. Neurological impairment was the symptom of Hypoaesthesia and Paraesthesia and Difficulty in walking (Gait disturbance) was the symptom of Rheumatoid arthritis. It was mentioned that patient was sick. The patient was a Cane user. 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 a 78-year-old female patient, with no reported medical history, who experienced the unexpected serious (medically significant) AESI Rheumatoid arthritis occurred on an unknown date in the context of receiving a dose of mRNA-1273 vaccine along with other non-serious events. Patient experienced rheumatoid arthritis flare up along with numbness and tingling of the feet, difficult ambulation aided with cane, muscle stiffness and tightness in legs. Erythrocyte sedimentation rate was reported high at 79 (unit not reported). Patient treated with Meloxicam. Patient received 1st and 2nd doses of mRNA-1273 vaccine 6 months apart. On an unknown date, patient received Adalimumab for rheumatoid arthritis which could be a confounder. The benefit-risk relationship of mRNA-1273 is not affected by this report.   Most recent FOLLOW-UP information incorporated above includes: On 06-Jul-2022: Live significant follow-up: Patient demographics, product & event information received and case seriousness upgraded to serious.; Sender's Comments: This spontaneous case concerns a 78-year-old female patient, with no reported medical history, who experienced the unexpected serious (medically significant) AESI Rheumatoid arthritis occurred on an unknown date in the context of receiving a dose of mRNA-1273 vaccine along with other non-serious events. Patient experienced rheumatoid arthritis flare up along with numbness and tingling of the feet, difficult ambulation aided with cane, muscle stiffness and tightness in legs. Erythrocyte sedimentation rate was reported high at 79 (unit not reported). Patient treated with Meloxicam. Patient received 1st and 2nd doses of mRNA-1273 vaccine 6 months apart. On an unknown date, patient received Adalimumab for rheumatoid arthritis which could be a confounder. The benefit-risk relationship of mRNA-1273 is not affected by this report.