left knee warmth; left knee swelling; woke up/collapsed after trying to get out of bed; felt fluish; felt weak/got weaken as day went on; fall; could not walk; joint infection; This spontaneous case was reported by a physician and describes the occurrence of SYNCOPE (woke up/collapsed after trying to get out of bed), GAIT INABILITY (could not walk), INFLUENZA LIKE ILLNESS (felt fluish), JOINT WARMTH (left knee warmth), JOINT SWELLING (left knee swelling), ASTHENIA (felt weak/got weaken as day went on), FALL (fall) and ARTHRITIS INFECTIVE (joint infection) in a 77-year-old female patient who received mRNA-1273 (Moderna COVID-19 Vaccine) (batch no. 030LZ0A) for COVID-19 vaccination.    Co-suspect product included non-company product ADALIMUMAB (HUMIRA) for Rheumatoid arthritis.    The patient's past medical history included Knee replacement (LEFT) in 2013. Previously administered products included for Hives: Amoxicillin. Past adverse reactions to the above products included Rash with Amoxicillin. Concurrent medical conditions included Tobacco user (30 TO 40 CIGARETTE STICKS A DAY) since 1962, Drug allergy (AMOXICILLIN-RASH AND HIVES), Abstains from alcohol, Diabetes, Blood pressure high, High cholesterol, Water retention and Rheumatoid arthritis. Concomitant products included LISINOPRIL for Blood pressure high, INSULIN GLARGINE (LANTUS) and INSULIN ASPART (NOVOLOG) for Diabetes, SIMVASTATIN for High cholesterol, HYDROCHLOROTHIAZIDE for Water retention and Blood pressure high, AMOXICILLIN for an unknown indication.   In September 2017, the patient started ADALIMUMAB (HUMIRA) (Subcutaneous) 40 mg. On 11-Feb-2021, the patient received first dose of mRNA-1273 (Moderna COVID-19 Vaccine) (Intramuscular) 1 dosage form. On 15-Mar-2021, ADALIMUMAB (HUMIRA) (Subcutaneous) dosage was changed to 40 mg. On 10-May-2021, ADALIMUMAB (HUMIRA) (Subcutaneous) dosage was changed to 40 mg. In February 2021, the patient experienced FALL (fall) (seriousness criteria hospitalization and medically significant). On 22-Feb-2021, the patient experienced INFLUENZA LIKE ILLNESS (felt fluish) (seriousness criteria hospitalization and medically significant) and ASTHENIA (felt weak/got weaken as day went on) (seriousness criteria hospitalization and medically significant). On 23-Feb-2021, the patient experienced SYNCOPE (woke up/collapsed after trying to get out of bed) (seriousness criteria hospitalization and medically significant) and GAIT INABILITY (could not walk) (seriousness criteria hospitalization and medically significant). On 25-Feb-2021, the patient experienced JOINT WARMTH (left knee warmth) (seriousness criteria hospitalization and medically significant) and JOINT SWELLING (left knee swelling) (seriousness criteria hospitalization and medically significant). On 17-Mar-2021, the patient experienced ARTHRITIS INFECTIVE (joint infection) (seriousness criteria hospitalization and medically significant). The patient was hospitalized from 23-Feb-2021 to 25-Feb-2021 due to GAIT INABILITY. The patient was treated with AMOXICILLIN SODIUM, CLAVULANATE POTASSIUM (AUGMENTIN [AMOXICILLIN SODIUM;CLAVULANATE POTASSIUM]) at a dose of 1 dosage form. In February 2021, SYNCOPE (woke up/collapsed after trying to get out of bed), JOINT WARMTH (left knee warmth) and FALL (fall) had resolved. In April 2021, GAIT INABILITY (could not walk) and JOINT SWELLING (left knee swelling) had resolved. At the time of the report, INFLUENZA LIKE ILLNESS (felt fluish) had not resolved and ASTHENIA (felt weak/got weaken as day went on) and ARTHRITIS INFECTIVE (joint infection) was resolving.      DIAGNOSTIC RESULTS (normal ranges are provided in parenthesis if available): On 17-Mar-2021, Laboratory test: left knee infection (abnormal) Left Knee Infection. On an unknown date, Culture: unspecified (Inconclusive) unspecified. On an unknown date, Laboratory test: showed no stroke (normal) Showed no stroke and unrecalled results (Inconclusive) Unrecalled results.     The action taken with mRNA-1273 (Moderna COVID-19 Vaccine) (Intramuscular) was unknown.   For mRNA-1273 (Moderna COVID-19 Vaccine) (Intramuscular), the reporter did not provide any causality assessments.   Treatment for the events included un-specified intravenous fluids and unspecified intravenous medications during her hospital stay. Patient stated that On 23 Mar 2021, she had a Left knee replacement surgery due to the  infection of the Stryker knee. Laboratory test include fluid sample test which results in Left Knee Infection on 17-mar-2021. Patient stated that her metal knee was replaced with a plastic knee patient went to rehabilitation on 02-apr-2021 and was discharged from rehabilitation care on 16-apr-2021. Patient stated that she was admitted for three days on 23 Feb 2021.On 02 Apr 2021, she  was discharged from hospital. It was reported that the patient had a culture test and unspecified laboratory test on an unknown date; results were not reported.  Based on the 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. However, patient's medical condition and co-administered drugs may be considered as a alternative explanation for the reported events.   This case was linked to MOD-2021-234196 (Patient Link).; Sender's Comments: Based on the 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. However, patient's medical condition and co-administered drugs may be considered as a alternative explanation for the reported events.