Had a fever of 103 degrees; Swelling continued at the injection site; Vaccination given subcutaneously; Swelling began that afternoon; Inflammation began that afternoon; Tissue had hardened; The area was very warm to touch; The arm pit area is still a little tender; Left arm below the deltoid was extremely red; Lymph nodes in left armpit were very painful for 2-3 days; Woke in middle of night chilling; Lymph nodes in left armpit were swollen; This spontaneous case was reported by a consumer and describes the occurrence of TENDERNESS (The arm pit area is still a little tender), ERYTHEMA (Left arm below the deltoid was extremely red), INFLAMMATION (Inflammation began that afternoon), INDURATION (Tissue had hardened) and FEELING HOT (The area was very warm to touch) in a female patient of an unknown age who received mRNA-1273 (Moderna COVID-19 Vaccine) (batch no. 044B21A) for COVID-19 vaccination. The occurrence of additional non-serious events is detailed below.     Concurrent medical conditions included Leukemia (Reported that no recent change in chronic condition) since 08-Jan-2006, Blood pressure high (HBP) and Seasonal allergy. Concomitant products included TRIAMTERENE for Blood pressure high, MONTELUKAST SODIUM (SINGULAIR) for Seasonal allergy, OMEPRAZOLE (PROTONIX [OMEPRAZOLE]) for an unknown indication.    On 10-Sep-2021 at 4:00 PM, the patient received third dose of mRNA-1273 (Moderna COVID-19 Vaccine) (Subcutaneous) 1 dosage form. On 10-Sep-2021, the patient experienced INFLAMMATION (Inflammation began that afternoon), SWELLING (Swelling began that afternoon) and INCORRECT ROUTE OF PRODUCT ADMINISTRATION (Vaccination given subcutaneously). On 10-Sep-2021 at 9:00 PM, the patient experienced VACCINATION SITE SWELLING (Swelling continued at the injection site). On 11-Sep-2021 at 1:00 AM, the patient experienced PYREXIA (Had a fever of 103 degrees). In September 2021, the patient experienced TENDERNESS (The arm pit area is still a little tender), ERYTHEMA (Left arm below the deltoid was extremely red), INDURATION (Tissue had hardened), FEELING HOT (The area was very warm to touch), LYMPH NODE PAIN (Lymph nodes in left armpit were very painful for 2-3 days), CHILLS (Woke in middle of night chilling) and LYMPHADENOPATHY (Lymph nodes in left armpit were swollen). On 10-Sep-2021, INCORRECT ROUTE OF PRODUCT ADMINISTRATION (Vaccination given subcutaneously) had resolved. On 13-Sep-2021, PYREXIA (Had a fever of 103 degrees) had resolved. In September 2021, LYMPH NODE PAIN (Lymph nodes in left armpit were very painful for 2-3 days) and LYMPHADENOPATHY (Lymph nodes in left armpit were swollen) had resolved. At the time of the report, TENDERNESS (The arm pit area is still a little tender), ERYTHEMA (Left arm below the deltoid was extremely red) and VACCINATION SITE SWELLING (Swelling continued at the injection site) had not resolved and INFLAMMATION (Inflammation began that afternoon), INDURATION (Tissue had hardened), FEELING HOT (The area was very warm to touch), SWELLING (Swelling began that afternoon) and CHILLS (Woke in middle of night chilling) outcome was unknown.      DIAGNOSTIC RESULTS (normal ranges are provided in parenthesis if available): In September 2021, Body temperature: 103 (High) 103 degrees which continued for the next 2-3 days to varying degrees but never below 100.         The concomitant medication Protonix was administered by the patient for reflux.  The patient was not diagnosed with COVID 19 and had no acute illness at the time of vaccination up to one month before. She was administered with third dose of vaccination due to reduced immune system.   The patient experienced swollen lymph nodes in her left armpit and was painful for about 2  3 days. The injection site which was below the deltoid and to the outside of her arm was still swollen and red but not as bad. She had not seeked any medical attention for swelling at injection site and fever. The patient reported that the adverse event was most likely caused by vaccine.   Most recent FOLLOW-UP information incorporated above includes: On 15-Sep-2021: Follow up document received. Patient demographics, medical history, vaccine details, concomitant medication and events were added. On 15-Sep-2021: Follow up document received on 16 Sep 2021 and contains no new information.