autoimmune condition; severe hives/continues to come back/body writing; This spontaneous case was reported by a patient family member or friend and describes the occurrence of AUTOIMMUNE DISORDER (autoimmune condition) in a 28-year-old female patient who received mRNA-1273 (Moderna COVID-19 Vaccine) for COVID-19 prophylaxis. The occurrence of additional non-serious events is detailed below.     Concurrent medical conditions included Seasonal allergy.   On 27-Feb-2021, the patient received first dose of mRNA-1273 (Moderna COVID-19 Vaccine) (unknown route) 1 dosage form. On 27-Mar-2021, received second dose of mRNA-1273 (Moderna COVID-19 Vaccine) (unknown route) dosage was changed to 1 dosage form. On an unknown date, the patient experienced AUTOIMMUNE DISORDER (autoimmune condition) (seriousness criterion medically significant) and URTICARIA (severe hives/continues to come back/body writing). The patient was treated with CETIRIZINE HYDROCHLORIDE (ZYRTEC [CETIRIZINE HYDROCHLORIDE]) for Autoimmune disorder, at an unspecified dose and frequency. At the time of the report, AUTOIMMUNE DISORDER (autoimmune condition) and URTICARIA (severe hives/continues to come back/body writing) had not resolved.            The patient was on no medications prior to getting the vaccines.  The reporter stated that, the hives was repetitive, continued to come back, pronounced and persistent.  The reporter said Zyrtec helped to control it. But if she delayed taking it the hives would come back out.  Company comment: This spontaneous case concerns a 28-year-old female patient with medical history of seasonal allergy, who experienced the unexpected serious (medically significant) event of Autoimmune disorder that occurred unknown days after receiving the second dose of mRNA-1273 vaccine in the Covid-19 vaccination series. Latency could not be assessed as the date on onset of the event was not available. Patient had received first dose of same vaccine approximately 28 days prior to the second dose. It was reported that the patient experienced a reaction(hives) after the first dose and it went away. After the second dose she developed severe hives, known as body writing, repetitive, continued to come back, pronounced and persistent. Patient saw an allergist and was treated with allergy medications. No further information regarding the risk factors additional medication history, detailed clinical course,  investigations and treatment received were provided. The outcome of the event was not recovered. The medical history of Seasonal allergy could be in association with the event. The benefit-risk relationship of mRNA-1273 is not affected by this report.   This case was linked to MOD-2022-682330 (Patient Link).; Sender's Comments: This spontaneous case concerns a 28-year-old female patient with medical history of seasonal allergy, who experienced the unexpected serious (medically significant) event of Autoimmune disorder that occurred unknown days after receiving the second dose of mRNA-1273 vaccine in the Covid-19 vaccination series. Latency could not be assessed as the date on onset of the event was not available. Patient had received first dose of same vaccine approximately 28 days prior to the second dose. It was reported that the patient experienced a reaction(hives) after the first dose and it went away. After the second dose she developed severe hives, known as body writing, repetitive, continued to come back, pronounced and persistent. Patient saw an allergist and was treated with allergy medications. No further information regarding the risk factors additional medication history, detailed clinical course,  investigations and treatment received were provided. The outcome of the event was not recovered. The medical history of Seasonal allergy could be in association with the event. The benefit-risk relationship of mRNA-1273 is not affected by this report.