Large reddened area at the injection site which is warm to touch / Injection site reddness; Injection site pain; Injection site swelling; Large reddened area at the injection site which is warm to touch; Progressively got larger and started itching approximately 2 hours after receiving the vaccine; This spontaneous case was reported by a nurse and describes the occurrence of VACCINATION SITE WARMTH (Large reddened area at the injection site which is warm to touch), VACCINATION SITE PRURITUS (Progressively got larger and started itching approximately 2 hours after receiving the vaccine), VACCINATION SITE ERYTHEMA (Large reddened area at the injection site which is warm to touch / Injection site reddness), VACCINATION SITE PAIN (Injection site pain) and VACCINATION SITE SWELLING (Injection site swelling) in a 20-year-old female patient who received mRNA-1273 (Moderna COVID-19 Vaccine) (batch no. 011J20A) for COVID-19 vaccination.     No Medical History information was reported.    On 06-Mar-2021 at 10:30 AM, the patient received first dose of mRNA-1273 (Moderna COVID-19 Vaccine) (Intramuscular) 1 dosage form. On 06-Mar-2021, the patient experienced VACCINATION SITE WARMTH (Large reddened area at the injection site which is warm to touch) and VACCINATION SITE PRURITUS (Progressively got larger and started itching approximately 2 hours after receiving the vaccine). On 06-Mar-2021 at 12:30 PM, the patient experienced VACCINATION SITE ERYTHEMA (Large reddened area at the injection site which is warm to touch / Injection site reddness), VACCINATION SITE PAIN (Injection site pain) and VACCINATION SITE SWELLING (Injection site swelling). The patient was treated with DIPHENHYDRAMINE HYDROCHLORIDE (BENADRYL [DIPHENHYDRAMINE HYDROCHLORIDE]) ongoing from March 2021 for Adverse event, at an unspecified dose and frequency. At the time of the report, VACCINATION SITE WARMTH (Large reddened area at the injection site which is warm to touch), VACCINATION SITE PRURITUS (Progressively got larger and started itching approximately 2 hours after receiving the vaccine), VACCINATION SITE ERYTHEMA (Large reddened area at the injection site which is warm to touch / Injection site reddness), VACCINATION SITE PAIN (Injection site pain) and VACCINATION SITE SWELLING (Injection site swelling) outcome was unknown.        The action taken with mRNA-1273 (Moderna COVID-19 Vaccine) (Intramuscular) was unknown.   For mRNA-1273 (Moderna COVID-19 Vaccine) (Intramuscular), the reporter considered VACCINATION SITE ERYTHEMA (Large reddened area at the injection site which is warm to touch / Injection site reddness), VACCINATION SITE PAIN (Injection site pain) and VACCINATION SITE SWELLING (Injection site swelling) to be probably related. No further causality assessments were provided for VACCINATION SITE WARMTH (Large reddened area at the injection site which is warm to touch) and VACCINATION SITE PRURITUS (Progressively got larger and started itching approximately 2 hours after receiving the vaccine).    No concomitant medication information was provided.   The patient also used ice to alleviate the adverse events.   Most recent FOLLOW-UP information incorporated above includes: On 01-Jul-2021: Follow-up information received on 01Jul 2021 contains significant information. ADR Form received.  Events and causality updated.