arm had knot the size of a baseball; had a knot the size of a baseball. Patient stated its really hard, painful, and could not lay on side of body; had a knot the size of a baseball. Patient stated its really hard, painful, and could not lay on side of body; had a knot the size of a baseball. Patient stated its really hard, painful, and could not lay on side of body; it felt like body was rejecting the vaccine; wondered if got a bad vaccine; it felt like he stabbed her arm when injecting; Myalgia; This spontaneous case was reported by a consumer and describes the occurrence of PAIN (Sore for a few days), MASS (arm had knot the size of a baseball), PAIN IN EXTREMITY (had a knot the size of a baseball. Patient stated its really hard, painful, and could not lay on side of body), LOSS OF PERSONAL INDEPENDENCE IN DAILY ACTIVITIES (had a knot the size of a baseball. Patient stated its really hard, painful, and could not lay on side of body) and SOFT TISSUE INJURY (had a knot the size of a baseball. Patient stated its really hard, painful, and could not lay on side of body) in a 73-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.     No Medical History information was reported.   On 09-Mar-2021, the patient received first dose of mRNA-1273 (Moderna COVID-19 Vaccine) (Intramuscular) 1 dosage form. On 12-Apr-2021, received second dose of mRNA-1273 (Moderna COVID-19 Vaccine) (unknown route) dosage was changed to 2 dosage form. On 09-Mar-2021, the patient experienced PAIN (Sore for a few days). On 12-Apr-2021, the patient experienced MASS (arm had knot the size of a baseball), PAIN IN EXTREMITY (had a knot the size of a baseball. Patient stated its really hard, painful, and could not lay on side of body), LOSS OF PERSONAL INDEPENDENCE IN DAILY ACTIVITIES (had a knot the size of a baseball. Patient stated its really hard, painful, and could not lay on side of body), SOFT TISSUE INJURY (had a knot the size of a baseball. Patient stated its really hard, painful, and could not lay on side of body), FEELING ABNORMAL (it felt like body was rejecting the vaccine), PRODUCT TEMPERATURE EXCURSION ISSUE (wondered if got a bad vaccine) and PRODUCT ADMINISTRATION ERROR (it felt like he stabbed her arm when injecting). At the time of the report, PAIN (Sore for a few days) had resolved and MASS (arm had knot the size of a baseball), PAIN IN EXTREMITY (had a knot the size of a baseball. Patient stated its really hard, painful, and could not lay on side of body), LOSS OF PERSONAL INDEPENDENCE IN DAILY ACTIVITIES (had a knot the size of a baseball. Patient stated its really hard, painful, and could not lay on side of body), SOFT TISSUE INJURY (had a knot the size of a baseball. Patient stated its really hard, painful, and could not lay on side of body), FEELING ABNORMAL (it felt like body was rejecting the vaccine), PRODUCT TEMPERATURE EXCURSION ISSUE (wondered if got a bad vaccine) and PRODUCT ADMINISTRATION ERROR (it felt like he stabbed her arm when injecting) outcome was unknown. Not Provided      The action taken with mRNA-1273 (Moderna COVID-19 Vaccine) (Unknown Route) and mRNA-1273 (Moderna COVID-19 Vaccine) (Intramuscular) was unknown.       No concomitant medications provided. No treatment information was provided.