Temperature in the injection site was 1 degree higher than the rest of the body; vaccination site rash; The injection site was red of the size of an orange for 7 to 10 days; The injection site was of the size of an orange for 7 to 10 days; This spontaneous case was reported by a consumer (subsequently medically confirmed) and describes the occurrence of VACCINATION SITE WARMTH (Temperature in the injection site was 1 degree higher than the rest of the body), VACCINATION SITE RASH (vaccination site rash), VACCINATION SITE ERYTHEMA (The injection site was red of the size of an orange for 7 to 10 days) and VACCINATION SITE SWELLING (The injection site was of the size of an orange for 7 to 10 days) in a 77-year-old male patient who received mRNA-1273 (Moderna COVID-19 Vaccine) (batch no. 037K20A) for COVID-19 vaccination.     Concurrent medical conditions included Seizures since 1991 and Type 2 diabetes mellitus since 1995. Concomitant products included VALPROATE SEMISODIUM (DIVALPROEX) for Seizures, METFORMIN for Type 2 diabetes mellitus, VITAMIN D3 for an unknown indication.    On 30-Dec-2020 at 4:30 PM, the patient received first dose of mRNA-1273 (Moderna COVID-19 Vaccine) (Intramuscular) 1 dosage form. On 01-Jan-2021, the patient experienced VACCINATION SITE WARMTH (Temperature in the injection site was 1 degree higher than the rest of the body), VACCINATION SITE RASH (vaccination site rash), VACCINATION SITE ERYTHEMA (The injection site was red of the size of an orange for 7 to 10 days) and VACCINATION SITE SWELLING (The injection site was of the size of an orange for 7 to 10 days). The patient was treated with LORATADINE (CLARITIN [LORATADINE]) for Adverse event, at a dose of UNK dosage form. At the time of the report, VACCINATION SITE WARMTH (Temperature in the injection site was 1 degree higher than the rest of the body) and VACCINATION SITE SWELLING (The injection site was of the size of an orange for 7 to 10 days) outcome was unknown and VACCINATION SITE RASH (vaccination site rash) and VACCINATION SITE ERYTHEMA (The injection site was red of the size of an orange for 7 to 10 days) had resolved.        mRNA-1273 (Moderna COVID-19 Vaccine) (Intramuscular) dosing remained unchanged.       Patient was sent to emergency room, where they determined it was bacterial infection and was treated with prescription for an antibiotic. Two days later, the patient's primary care doctor called and stated that that it was a viral infection and to take Claritin (Loratadine). The redness went away in two days Patient also reported that, allergic reactions were other potential causes for adverse events.   This case was linked to MOD-2021-017819 (Patient Link).   Most recent FOLLOW-UP information incorporated above includes: On 05-Apr-2021: Follow up information was received: more detailed address, ethnicity, height, weight of the patient added.Concomitant medications, medical history of patient added. New adverse event viral infection and red rash added, narrative updated; Sender's Comments: Based on the current available information and temporal association between the use of the product and the start date of the events, a causal relationship cannot be excluded.