This spontaneous case was reported by a physician and describes the occurrence of RHEUMATOID ARTHRITIS (Rheumatoid arthritis flare) in a 61-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 products included non-company products ADALIMUMAB (HUMIRA) for Rheumatoid arthritis, PROMETHAZINE (PHENERGAN [PROMETHAZINE]) for an unknown indication, AZITHROMYCIN (Z-PAK) for an unknown indication and OXYBUTYNIN for an unknown indication. The patient's past medical history included Back pain in 2018. Concurrent medical conditions included Rheumatoid arthritis (Moderate to severe). In 2013, the patient ADALIMUMAB (HUMIRA) (Subcutaneous) dosage was changed to 1 dosage form every two weeks. On an unknown date, the patient received second 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, ADALIMUMAB (HUMIRA) (Subcutaneous) Citrate Free, UNK and ADALIMUMAB (HUMIRA) (Subcutaneous) dosage was changed to Citrate Free, UNK., PROMETHAZINE (PHENERGAN [PROMETHAZINE]) (Subcutaneous) at an unspecified dose, AZITHROMYCIN (Z-PAK) (unknown route) at an unspecified dose and OXYBUTYNIN (unknown route) at an unspecified dose. In December 2020, the patient experienced RHEUMATOID ARTHRITIS (Rheumatoid arthritis flare) (seriousness criterion medically significant). On 04-Mar-2021, the patient experienced NASAL CONGESTION (Stuffy nose) and HYPERSENSITIVITY (Allergy symptoms). In March 2021, the patient experienced ARTHRITIS (Arthritis) and PERIPHERAL SWELLING (One leg swollen). On an unknown date, the patient experienced RASH ERYTHEMATOUS (Had rash near eye / rash that looked like red bites / left leg and right arm rash), ADVERSE DRUG REACTION (Reaction to Humira with COVID vaccine with Humira), DRUG INTERACTION (Reaction to Humira with COVID vaccine with Humira), FEELING HOT (Got real hot after taking Phenergan), FEELING ABNORMAL (Feeling bad), INFLAMMATION (Inflammation), NASOPHARYNGITIS (Cold), MUSCLE SPASMS (Knee cramping), MUSCULOSKELETAL DISCOMFORT (Disk in back bothering/bother/woke up with upper back was bothering and cause discomfort), INTERVERTEBRAL DISC DISORDER (Discopathy), NECK PAIN, FUNGAL SKIN INFECTION (Yeast infection under breast and abdomen), LEFT EYE SWELLING, UNEVALUABLE EVENT, PRURITUS (Itching on arms and legs), DIARRHOEA (Diarrhea), INJECTION SITE PRURITUS (Arm itched real bad after COVID vaccine) and NAUSEA (Nauseous). At the time of the report, RHEUMATOID ARTHRITIS (Rheumatoid arthritis flare), FEELING ABNORMAL (Feeling bad), MUSCLE SPASMS (Knee cramping), HYPERSENSITIVITY (Allergy symptoms) and PERIPHERAL SWELLING (One leg swollen) had not resolved, RASH ERYTHEMATOUS (Had rash near eye / rash that looked like red bites / left leg and right arm rash) and INJECTION SITE PRURITUS (Arm itched real bad after COVID vaccine) had resolved, ADVERSE DRUG REACTION (Reaction to Humira with COVID vaccine with Humira), DRUG INTERACTION (Reaction to Humira with COVID vaccine with Humira), FEELING HOT (Got real hot after taking Phenergan), NASAL CONGESTION (Stuffy nose), FUNGAL SKIN INFECTION (Yeast infection under breast and abdomen), UNEVALUABLE EVENT (unevaluable event), DIARRHOEA (Diarrhea) and NAUSEA (Nauseous) was resolving and INFLAMMATION (Inflammation), ARTHRITIS (Arthritis), NASOPHARYNGITIS (Cold), MUSCULOSKELETAL DISCOMFORT (Disk in back bothering/bother/woke up with upper back was bothering and cause discomfort), INTERVERTEBRAL DISC DISORDER (Discopathy), NECK PAIN (Neck pain), EYE SWELLING (Left eye swelling) and PRURITUS (Itching on arms and legs) outcome was unknown. DIAGNOSTIC RESULTS (normal ranges are provided in parenthesis if available): In March 2021, X-ray: arthritis (abnormal) Arthritis. For mRNA-1273 (Moderna COVID-19 Vaccine) (Intramuscular), the reporter considered INJECTION SITE PRURITUS (Arm itched real bad after COVID vaccine) to be possibly related and RHEUMATOID ARTHRITIS (Rheumatoid arthritis flare), RASH ERYTHEMATOUS (Had rash near eye / rash that looked like red bites / left leg and right arm rash), DRUG INTERACTION (Reaction to Humira with COVID vaccine with Humira), FEELING HOT (Got real hot after taking Phenergan), FEELING ABNORMAL (Feeling bad), INFLAMMATION (Inflammation), NASAL CONGESTION (Stuffy nose), ARTHRITIS (Arthritis), NASOPHARYNGITIS (Cold), MUSCLE SPASMS (Knee cramping), HYPERSENSITIVITY (Allergy symptoms), PERIPHERAL SWELLING (One leg swollen), MUSCULOSKELETAL DISCOMFORT (Disk in back bothering/bother/woke up with upper back was bothering and cause discomfort), INTERVERTEBRAL DISC DISORDER (Discopathy), NECK PAIN (Neck pain), FUNGAL SKIN INFECTION (Yeast infection under breast and abdomen), EYE SWELLING (Left eye swelling), UNEVALUABLE EVENT, PRURITUS (Itching on arms and legs), DIARRHEA and NAUSEA to have a relationship that was not reported, ADVERSE DRUG REACTION (Reaction to Humira with COVID vaccine with Humira) to be not applicable. It was unknown if the patient was enrolled in a COVID-19 vaccine trial. On an unknown date, the patient received her first dose of the COVID-19 Vaccine/Placebo manufactured by Moderna. On an unknown date, the patient received her second dose of the COVID-19 vaccine, manufactured by Moderna. Promethazine (PHENERGAN), azithromycin (Z-PAK), Oxybutynin, and adalimumab (HUMIRA) were also considered suspect. Concomitant drugs were not reported. The patient was treated with hydrocodone, prednisone, tramadol and loperamide (IMODIUM). On an unknown date, the pain scale was 8. On an unknown date, the patient underwent a vitamin D test to check for gout and a uric acid test (results not provided). This case concerns a 61-year-old female with a serious unexpected event of rheumatoid arthritis flare up, and multiple nonserious unexpected events including hypersensitivity, arthritis, rash erythematous, drug interaction, and inflammation. Latency unknown after mRNA-1273. She received both first and second doses. Based on current available information and temporal association between the use of the product and the start date of the event, a causal relationship cannot be excluded. Most recent FOLLOW-UP information incorporated above includes: On 27-Apr-2021: No specific follow-up information recorded.; Sender's Comments: This case concerns a 61-year-old female with a serious unexpected event of rheumatoid arthritis flare up, and multiple nonserious unexpected events including hypersensitivity, arthritis, rash erythematous, drug interaction, and inflammation. Latency unknown after mRNA-1273. She received both first and second doses. Based on current available information and temporal association between the use of the product and the start date of the event, a causal relationship cannot be excluded.