One doctor said it's rheumatoid arthritis but her blood tests don't show that.; pain is in her hands and feet/pain is in her feet/extreme pain; headache; joint pain; knee pain/ elbow pain/ wrist pain; fatigue/ Feels very tired; chills; fever; swelling of the feet; lower back pain; tingling sensation in fingers; This spontaneous case was reported by a consumer (subsequently medically confirmed) and describes the occurrence of RHEUMATOID ARTHRITIS (One doctor said it's rheumatoid arthritis but her blood tests don't show that.) in a 79-year-old female patient who received mRNA-1273 (Moderna COVID-19 Vaccine) (batch nos. 001B21A and 029L20A) for COVID-19 vaccination. The occurrence of additional non-serious events is detailed below.     No Medical History information was reported.   On 11-Feb-2021, the patient received first dose of mRNA-1273 (Moderna COVID-19 Vaccine) (Intramuscular) 1 dosage form. On 13-Mar-2021, received second dose of mRNA-1273 (Moderna COVID-19 Vaccine) (Intramuscular) dosage was changed to 1 dosage form. On 14-Mar-2021, the patient experienced PERIPHERAL SWELLING (swelling of the feet), BACK PAIN (lower back pain), PARAESTHESIA (tingling sensation in fingers), HEADACHE (headache), ARTHRALGIA (joint pain), ARTHRALGIA (knee pain/ elbow pain/ wrist pain), FATIGUE (fatigue/ Feels very tired), CHILLS (chills) and PYREXIA (fever). In May 2021, the patient experienced RHEUMATOID ARTHRITIS (One doctor said it's rheumatoid arthritis but her blood tests don't show that.) (seriousness criterion medically significant) and PAIN IN EXTREMITY (pain is in her hands and feet/pain is in her feet/extreme pain). On 15-Mar-2021, HEADACHE (headache), ARTHRALGIA (joint pain) and PYREXIA (fever) had resolved. At the time of the report, RHEUMATOID ARTHRITIS (One doctor said it's rheumatoid arthritis but her blood tests don't show that.), PERIPHERAL SWELLING (swelling of the feet), BACK PAIN (lower back pain), PARAESTHESIA (tingling sensation in fingers), PAIN IN EXTREMITY (pain is in her hands and feet/pain is in her feet/extreme pain), ARTHRALGIA (knee pain/ elbow pain/ wrist pain), FATIGUE (fatigue/ Feels very tired) and CHILLS (chills) had not resolved.            No concomitant medication was provided by the reporter.  Patient experienced headache, body aches, joint pain, chills and fever swelling of the feet, knee pain, elbow pain, lower back pain, wrist pain, fatigue, very tired and tingling sensation in fingers after second dose of moderna vaccine.  Patient called in to give some updates about the side effects that she was still experiencing until now. It was her second time to call Moderna and she said she still have symptoms.  She said she already went to her two primary doctors but had not figured out yet as to what was going on with her. She was planning to visit her rheumatologist anytime this week for her third consultation.  One of the treating physician, told it was a rheumatoid arthritis but her blood tests don't show that.  No treatment medication was provided by the reporter.  Company Comment: This case concerns a 79-year-old female patient with no reported medical history who experienced the unexpected event of rheumatoid arthritis. The event occurred 1 day after the second dose of mRNA-1273. The rechallenge was unknown as no details about first dose was disclosed... Causality assessment for the reported event was not provided by the reporter. The benefit-risk relationship of mRNA-1273 is not affected by this report. Some patients are known to have experienced autoimmune disease reactivation following vaccine administration.   Most recent FOLLOW-UP information incorporated above includes: On 20-Sep-2021: Follow-up received contains new events of rheumatoid arthritis, pain in her hand and feet/pain in her feet and extreme pain.; Sender's Comments: This case concerns a 79-year-old female patient with no reported medical history who experienced the unexpected event of rheumatoid arthritis. The event occurred 1 day after the second dose of mRNA-1273. The rechallenge was unknown as no details about first dose was disclosed... Causality assessment for the reported event was not provided by the reporter. The benefit-risk relationship of mRNA-1273 is not affected by this report. Some patients are known to have experienced autoimmune disease reactivation following vaccine administration.