Knee replacement; KNEE REPLACEMENT; VACCINE INJECTION SITE HURT; FATIGUED; This spontaneous case was reported by a consumer and describes the occurrence of ARTHRALGIA (KNEE REPLACEMENT) and KNEE ARTHROPLASTY (Knee replacement) 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 product included non-company product ADALIMUMAB (HUMIRA) for Rheumatoid arthritis.    Concurrent medical conditions included Rheumatoid arthritis (Moderate to Severe).   On 16-Apr-2021, the patient received first dose of mRNA-1273 (Moderna COVID-19 Vaccine) (Intramuscular) 1 dosage form. On 21-May-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) Solution for injection in pre-filled pen. In 2021, the patient experienced VACCINATION SITE PAIN (VACCINE INJECTION SITE HURT) and FATIGUE (FATIGUED). On 28-Sep-2021, the patient experienced ARTHRALGIA (KNEE REPLACEMENT) (seriousness criterion medically significant). On an unknown date, the patient experienced KNEE ARTHROPLASTY (Knee replacement) (seriousness criterion medically significant). In 2021, VACCINATION SITE PAIN (VACCINE INJECTION SITE HURT) and FATIGUE (FATIGUED) had resolved. At the time of the report, ARTHRALGIA (KNEE REPLACEMENT) and KNEE ARTHROPLASTY (Knee replacement) was resolving.            It was unknown if patient was enrolled in a COVID-19 Vaccine Trial.  No concomitant medication were reported.  The reporters causality for the events of KNEE REPLACEMENT, STILL IN LOT OF PAIN onset 28 Sep 2021, VACCINE INJECTION SITE HURT, FATIGUED and KNEE REPLACEMENT, STILL IN LOT OF PAIN unknown onset was not provided.  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 is a Spontaneous case reported by a consumer, concerning a 61-year-old female patient, with relevant medical condition of rheumatoid arthritis, who experienced the unexpected and serious (due to medically significant) events of Arthralgia and Knee replacement, which occurred approximately 4 months after the second dose of mRNA-1273 vaccine. Co-suspect product includes non-company product Adalimumab for rheumatoid arthritis. At the time of the report, Knee replacement was resolving and Arthralgia had not resolved. No information disclosed about diagnostic tests performed. Rheumatoid arthritis remains a confounder for the events. The benefit-risk relationship of mRNA-1273 vaccine, is not affected by this report.; Sender's Comments: This is a Spontaneous case reported by a consumer, concerning a 61-year-old female patient, with relevant medical condition of rheumatoid arthritis, who experienced the unexpected and serious (due to medically significant) events of Arthralgia and Knee replacement, which occurred approximately 4 months after the second dose of mRNA-1273 vaccine. Co-suspect product includes non-company product Adalimumab for rheumatoid arthritis. At the time of the report, Knee replacement was resolving and Arthralgia had not resolved. No information disclosed about diagnostic tests performed. Rheumatoid arthritis remains a confounder for the events. The benefit-risk relationship of mRNA-1273 vaccine, is not affected by this report.