Anaphylactic reaction; Discomfort in his throat; Allergic reaction; Itching/touches his skin, he gets rashes which are itchy, red hives and would last for 30-40 minutes; Sweating a lot; Severe rashes all over his body; This spontaneous case was reported by a consumer and describes the occurrence of ANAPHYLACTIC REACTION (Anaphylactic reaction) in a 31-year-old male patient who received mRNA-1273 (Moderna COVID-19 Vaccine) (batch no. 031H21A) for COVID-19 vaccination. The occurrence of additional non-serious events is detailed below.     Concomitant products included INFLUENZA VACCINE (FLU) for an unknown indication.    On 01-Dec-2021, the patient received third dose of mRNA-1273 (Moderna COVID-19 Vaccine) (unknown route) 1 dosage form. On 05-Dec-2021, the patient experienced PRURITUS (Itching/touches his skin, he gets rashes which are itchy, red hives and would last for 30-40 minutes), HYPERHIDROSIS (Sweating a lot) and RASH (Severe rashes all over his body). On 17-Dec-2021, the patient experienced HYPERSENSITIVITY (Allergic reaction). On 24-Dec-2021, the patient experienced ANAPHYLACTIC REACTION (Anaphylactic reaction) (seriousness criterion medically significant) and OROPHARYNGEAL DISCOMFORT (Discomfort in his throat). The patient was treated with CETIRIZINE on 23-Dec-2021 for Rash, at a dose of 2 tabs at night; FEXOFENADINE HYDROCHLORIDE (ALLEGRA [FEXOFENADINE HYDROCHLORIDE]) for Rash, at a dose of 2 tabs in the morning; DEXAMETHASONE ACETATE (DECADRON [DEXAMETHASONE ACETATE]) on 24-Dec-2021 for Rash, at an unspecified dose and frequency and METHYLPREDNISOLONE ACETATE (MEDROL [METHYLPREDNISOLONE ACETATE]) for Rash, at an unspecified dose and frequency. At the time of the report, ANAPHYLACTIC REACTION (Anaphylactic reaction), OROPHARYNGEAL DISCOMFORT (Discomfort in his throat), PRURITUS (Itching/touches his skin, he gets rashes which are itchy, red hives and would last for 30-40 minutes), HYPERHIDROSIS (Sweating a lot) and HYPERSENSITIVITY (Allergic reaction) outcome was unknown and RASH (Severe rashes all over his body) had not resolved.      DIAGNOSTIC RESULTS (normal ranges are provided in parenthesis if available): On an unknown date, Allergy test: normal (normal) Normal. On an unknown date, Liver function test: normal (normal) Normal. On an unknown date, Renal function test: normal (normal) Normal.         Patient took home medications initially after severe itching and also said that he was using a newly brought comforter at that time. On 17Dec2021, since his rashes did not resolve, he saw a doctor who said that he was having an allergic reaction. He gave him steroid injection and oral steroids to be taken for 5 days. On 24Dec2021 he was prescribed with oral steroids and sent home back after 30 minutes. On 25Dec2021 he asked to continue with Allegra and Zyrtec by his allergist. Patient had his 1st dose on 07Apr2021; lot number 027B21A and 2nd dose on 05May2021; lot number 027C21A.  Company comment:  This case concerns a 31-year-old male patient, with no reported medical history, who experienced the serious  (medically significant according to Authority report), unexpected event of anaphylactic reaction. The patient experienced pruritus, hyperhidrosis, and rash 4 days after the third dose of mRNA 1273 COVID-19 vaccine, he took home medication. The symptoms did not resolve, hence he went to see a doctor and was given antihistamine. Twenty three days after the vaccine, patient had throat discomfort, he went to the emergency room  and  was diagnosed with anaphylactic reaction, he was given Decadron and oral steroids and sent home after 30 minutes. Patient called his allergist, and was given antihistamines.  At the time of report, patient was still having rashes on and off. The benefit-risk relationship of mRNA 1273 vaccine is not affected by this report.   This case was linked to MOD-2022-456439 (Patient Link).; Sender's Comments: This case concerns a 31-year-old male patient, with no reported medical history, who experienced the serious  (medically significant according to Authority report), unexpected event of anaphylactic reaction. The patient experienced pruritus, hyperhidrosis, and rash 4 days after the third dose of mRNA 1273 COVID-19 vaccine, he took home medication. The symptoms did not resolve, hence he went to see a doctor and was given antihistamine. Twenty three days after the vaccine, patient had throat discomfort, he went to the emergency room  and  was diagnosed with anaphylactic reaction, he was given Decadron and oral steroids and sent home after 30 minutes. Patient called his allergist, and was given antihistamines.  At the time of report, patient was still having rashes on and off. The benefit-risk relationship of mRNA 1273 vaccine is not affected by this report.