achyness; Her arm feels really hot; tender to the touch; generalized soreness in that area; started forming a big knot; arm was swollen/swelling on the deltoid; it was red/redness is spreading/redness is 12 millimeters long x 7 millimeters wide/redness continues to spread despite medication; This spontaneous case was reported by a consumer and describes the occurrence of MASS (started forming a big knot), TENDERNESS (tender to the touch), PAIN (achyness), VACCINATION SITE WARMTH (Her arm feels really hot) and VACCINATION SITE SWELLING (arm was swollen/swelling on the deltoid) in a 66-year-old female patient who received mRNA-1273 (Moderna COVID-19 Vaccine) (batch nos. 066F21A, 043L20A and 037K20A) for COVID-19 vaccination. The occurrence of additional non-serious events is detailed below.     No Medical History information was reported.  Concomitant products included BUDESONIDE, FORMOTEROL FUMARATE (SYMBICORT), PROGESTERONE and ESTRADIOL (ESTROGEN) for an unknown indication.   On 29-Dec-2020, the patient received first dose of mRNA-1273 (Moderna COVID-19 Vaccine) (Intramuscular) 1 dosage form. On 26-Jan-2021, received second dose of mRNA-1273 (Moderna COVID-19 Vaccine) (unknown route) dosage was changed to 1 dosage form. On 20-Nov-2021, received third dose of mRNA-1273 (Moderna COVID-19 Vaccine) (unknown route) dosage was changed to 1 dosage form. On 21-Nov-2021, the patient experienced MASS (started forming a big knot), VACCINATION SITE SWELLING (arm was swollen/swelling on the deltoid) and VACCINATION SITE ERYTHEMA (it was red/redness is spreading/redness is 12 millimeters long x 7 millimeters wide/redness continues to spread despite medication). On 22-Nov-2021, the patient experienced TENDERNESS (tender to the touch), VACCINATION SITE WARMTH (Her arm feels really hot) and MYALGIA (generalized soreness in that area). On an unknown date, the patient experienced PAIN (achyness). The patient was treated with IBUPROFEN (ADVIL [IBUPROFEN]) on 22-Nov-2021 for Adverse event, at an unspecified dose and frequency; PARACETAMOL (TYLENOL [PARACETAMOL]) on 22-Nov-2021 for Ache, at an unspecified dose and frequency; DIPHENHYDRAMINE HYDROCHLORIDE (BENADRYL [DIPHENHYDRAMINE HYDROCHLORIDE]) on 22-Nov-2021 for Adverse event, at an unspecified dose and frequency and LORATADINE (CLARITIN [LORATADINE]) on 22-Nov-2021 for Adverse event, at an unspecified dose and frequency. At the time of the report, MASS (started forming a big knot), TENDERNESS (tender to the touch), VACCINATION SITE WARMTH (Her arm feels really hot), VACCINATION SITE SWELLING (arm was swollen/swelling on the deltoid) and MYALGIA (generalized soreness in that area) outcome was unknown, PAIN (achyness) was resolving and VACCINATION SITE ERYTHEMA (it was red/redness is spreading/redness is 12 millimeters long x 7 millimeters wide/redness continues to spread despite medication) had not resolved.            The patient stated that the redness was 12 millimeters long x 7 millimeters wide.  Her arm felt really hot, redness continues to spread despite medication.  There was swelling on the deltoid. She had generalized soreness in that area and it was tender to the touch.   The Tylenol relieved some achiness.