hypersensitivity reaction; This spontaneous case was reported by a consumer and describes the occurrence of HYPERSENSITIVITY (hypersensitivity reaction) in a 70-year-old female patient who received mRNA-1273 (Moderna COVID-19 Vaccine) (batch no. 010M20A) for COVID-19 vaccination.     The patient's past medical history included Anaphylaxis. Concurrent medical conditions included Drug allergy (Naprosyn - Annaphylactic shock(on ventilator for 2 days)) since 01-Feb-1994, Sulfonamide allergy (Sulfa - Hives until drug stopped) since 1987, Aspirin asthma (Aspirin - Asthma attack) since 1986, Asthma since 1987 and Hives. Concomitant products included FLUTICASONE PROPIONATE, SALMETEROL XINAFOATE (ADVAIR) from 1990 to an unknown date for Asthma, CALCIUM from 1997 to an unknown date for Bone density abnormal, FLUTICASONE PROPIONATE (FLONASE [FLUTICASONE PROPIONATE]) from 1990 to an unknown date for Polyps, VITAMINS NOS from 2000 to an unknown date for Vitamin deficiency NOS.    On 04-Feb-2021, the patient received first dose of mRNA-1273 (Moderna COVID-19 Vaccine) (Intramuscular) 1 dosage form. On 06-Feb-2021, the patient experienced HYPERSENSITIVITY (hypersensitivity reaction) (seriousness criterion medically significant). The patient was treated with FEXOFENADINE HYDROCHLORIDE (ALLEGRA [FEXOFENADINE HYDROCHLORIDE]) in 2021 for Adverse event, at a dose of UNK, qid; PREDNISONE (oral) on 29-Mar-2021 for Adverse event, at a dose of 20 mg, daily; BETAMETHASONE (CELESTONE [BETAMETHASONE]) (intramuscular) on 02-Apr-2021 for Adverse event, at an unspecified dose and frequency and FAMOTIDINE (PEPCID [FAMOTIDINE]) (oral) for Adverse event, at a dose of UNK, qd. At the time of the report, HYPERSENSITIVITY (hypersensitivity reaction) had not resolved.      DIAGNOSTIC RESULTS (normal ranges are provided in parenthesis if available): On 23-Feb-2021, Blood pressure measurement: normal (normal) 124/72 mmHg. On 23-Feb-2021, Body temperature: normal (normal) 97.7. On 23-Feb-2021, Heart rate: normal (normal) 68 beats per minute. On 23-Feb-2021, Respiratory rate: normal (normal) 18 breaths per minute. On 01-Apr-2021, Antinuclear antibody: negative (Negative) Negative. On 01-Apr-2021, Blood immunoglobulin E: normal (normal) 46 Int unit/ml. On 01-Apr-2021, C-reactive protein: high (High) 0.7. On 01-Apr-2021, Complement factor: normal (normal) C3 - 151 mg/dl C4 - 33.1 mg/dl. On 01-Apr-2021, Mast cell degranulation test: normal (normal) 8.2 mcg/L.     The action taken with mRNA-1273 (Moderna COVID-19 Vaccine) (Intramuscular) was unknown.   For mRNA-1273 (Moderna COVID-19 Vaccine) (Intramuscular), the reporter did not provide any causality assessments.   Medical history of hives for 3 months 31-JUL-2017 with unknown cause. Concomitant medications also included HRT since 2001 po or patch daily and indication was provided as hormone replacement therapy. Patient stated that he had minimal hives and occasional allegra.  Company comment: This is a spontaneous case concerning a 70-year-old female patient with medical history of asthma, several medication allergies, anaphylactic shock and hives who experienced the unexpected and serious event of hypersensitivity. The event occurred 2 days after a first dose of mRNA-1273 vaccine was administered. The rechallenge was not applicable since only information of one dose was disclosed. Medical history of asthma, several medication allergies, anaphylactic shock and hives remains as confounders. Patient experienced hives, itching, angioedema, swelling of upper airway and tingling; medical intervention was required. Patient received antihistamines and steroids.  The benefit-risk relationship of the mRNA-1273 vaccine is not affected by this report.   Most recent FOLLOW-UP information incorporated above includes: On 02-Dec-2021: Significant follow-up received includes Case upgraded to Serious, Updated patient demographics, medical history, lab data, product details, concomitant and treatment medications, events added and outcome updated, Added reporter details.; Sender's Comments: This is a spontaneous case concerning a 70-year-old female patient with medical history of asthma, several medication allergies, anaphylactic shock and hives who experienced the unexpected and serious event of hypersensitivity. The event occurred 2 days after a first dose of mRNA-1273 vaccine was administered. The rechallenge was not applicable since only information of one dose was disclosed. Medical history of asthma, several medication allergies, anaphylactic shock and hives remains as confounders. Patient experienced hives, itching, angioedema, swelling of upper airway and tingling; medical intervention was required. Patient received antihistamines and steroids.  The benefit-risk relationship of the mRNA-1273 vaccine is not affected by this report.