I had anaphylaxis; I had trouble breathing; I felt my throat closing; palpitations; I slept for 3 days; arm pain for 3-4 days; fever; fatigue - I slept for 3 days; chills; This spontaneous case was reported by a consumer and describes the occurrence of ANAPHYLACTIC REACTION (I had anaphylaxis) in a 26-year-old female patient who received mRNA-1273 (Moderna COVID-19 Vaccine) (batch nos. 010M20A, 028L20A and 013F21A) for COVID-19 vaccination. The occurrence of additional non-serious events is detailed below.     Concurrent medical conditions included Asthma.   On 25-Jan-2021, the patient received first dose of mRNA-1273 (Moderna COVID-19 Vaccine) (unknown route) 1 dosage form. On 23-Feb-2021, received second dose of mRNA-1273 (Moderna COVID-19 Vaccine) (unknown route) dosage was changed to 1 dosage form. On 29-Nov-2021, received third dose of mRNA-1273 (Moderna COVID-19 Vaccine) (unknown route) dosage was changed to 1 dosage form. On 23-Feb-2021, the patient experienced ANAPHYLACTIC REACTION (I had anaphylaxis) (seriousness criterion medically significant), DYSPNOEA (I had trouble breathing), THROAT TIGHTNESS (I felt my throat closing), PALPITATIONS (palpitations), HYPERSOMNIA (I slept for 3 days), INJECTION SITE PAIN (arm pain for 3-4 days), PYREXIA (fever), FATIGUE (fatigue - I slept for 3 days) and CHILLS (chills). The patient was treated with IBUPROFEN (ADVIL [IBUPROFEN]) in 2021 for Adverse event, at an unspecified dose and frequency and DIPHENHYDRAMINE HYDROCHLORIDE (BENADRYL [DIPHENHYDRAMINE HYDROCHLORIDE]) in February 2021 for Adverse event, at a dose of 25 mg. At the time of the report, ANAPHYLACTIC REACTION (I had anaphylaxis), DYSPNOEA (I had trouble breathing), THROAT TIGHTNESS (I felt my throat closing), PALPITATIONS (palpitations), HYPERSOMNIA (I slept for 3 days), PYREXIA (fever), FATIGUE (fatigue - I slept for 3 days) and CHILLS (chills) outcome was unknown and INJECTION SITE PAIN (arm pain for 3-4 days) had resolved.            Concomitant medication was not provided by the reporter. The Inhaler was provided as a treatment medication.  Company comment: This case concerns a 26-year-old female patient with a medical history of asthma, who experienced the expected, serious (medically significant) event of anaphylaxis. The event occurred approximately 1 month after the first dose of mRNA-1273 and 20 minutoes after the second. The rechallenge was unknown since information about the outcome of events has not been provided, even though the patient reports that she experienced similar events after dose 1 and 2. The medical history of asthma is a confounder for throat tightness and dyspnoea, which are the symptoms described as "anaphylaxis". According to the Brighton collaboration criteria, there is insufficient evidence to meet any of levels of diagnostic certainty. The benefit-risk relationship of mRNA-1273 is not affected by this report.   This case was linked to MOD-2021-403695, MOD-2021-403815 (Patient Link).   Most recent FOLLOW-UP information incorporated above includes: On 02-Dec-2021: Follow-up received and included no new information.; Sender's Comments: This case concerns a 26-year-old female patient with a medical history of asthma, who experienced the expected, serious (medically significant) event of anaphylaxis. The event occurred approximately 1 month after the first dose of mRNA-1273 and 20 minutoes after the second. The rechallenge was unknown since information about the outcome of events has not been provided, even though the patient reports that she experienced similar events after dose 1 and 2. The medical history of asthma is a confounder for throat tightness and dyspnoea, which are the symptoms described as "anaphylaxis". According to the Brighton collaboration criteria, there is insufficient evidence to meet any of levels of diagnostic certainty. The benefit-risk relationship of mRNA-1273 is not affected by this report.