two hours later, she was cyanotic, lips, hands, and feet were blue; She had no heartbeat; was not breathing; She was completely unresponsive; They took her to the hospital and worked on her for a couple hours and then pronounced her dead; feeling very tired; an hour later, and she was snoring heavily; This spontaneous case was reported by a consumer and describes the occurrence of CYANOSIS (two hours later, she was cyanotic, lips, hands, and feet were blue), CARDIAC ARREST (She had no heartbeat), APNOEA (was not breathing), LOSS OF CONSCIOUSNESS (She was completely unresponsive) and DEATH (They took her to the hospital and worked on her for a couple hours and then pronounced her dead ) in a 57-year-old female patient who received mRNA-1273 (Moderna COVID-19 Vaccine) for COVID-19 vaccination. The occurrence of additional non-serious events is detailed below.     No Medical History information was reported.    On 03-Oct-2021 at 11:00 AM, the patient received first dose of mRNA-1273 (Moderna COVID-19 Vaccine) (unknown route) 1 dosage form. On 03-Oct-2021, the patient experienced CYANOSIS (two hours later, she was cyanotic, lips, hands, and feet were blue) (seriousness criterion death), FATIGUE (feeling very tired) and SNORING (an hour later, and she was snoring heavily). 03-Oct-2021, the patient experienced CARDIAC ARREST (She had no heartbeat) (seriousness criteria death and medically significant), APNOEA (was not breathing) (seriousness criteria death and medically significant), LOSS OF CONSCIOUSNESS (She was completely unresponsive) (seriousness criteria death and medically significant) and DEATH (They took her to the hospital and worked on her for a couple hours and then pronounced her dead) (seriousness criteria death and medically significant). On 03-Oct-2021, FATIGUE (feeling very tired) and SNORING (an hour later, and she was snoring heavily) outcome was unknown. The patient died on 03-Oct-2021. The cause of death was not reported. It is unknown if an autopsy was performed.            No concomitant medication information were provided. No treatment information were provided. The patient was taken to hospital and after a couple of hours, she was pronounced to be dead.  Company Comment: This case concerns a 57-year-old female with no relevant medical history, who experienced the unexpected event of cyanosis. The event occurred the same day after receiving the first dose of mRNA-1273 (Moderna COVID-19 Vaccine) and had a fatal outcome, with death occurring the same day. The cause of death was not reported. It is unknown if an autopsy was performed. The rechallenge was not applicable, as the event happened after the first dose. The benefit-risk relationship of mRNA-1273 (Moderna COVID-19 Vaccine) is not affected by this report.; Sender's Comments: This case concerns a 57-year-old female with no relevant medical history, who experienced the unexpected event of cyanosis. The event occurred the same day after receiving the first dose of mRNA-1273 (Moderna COVID-19 Vaccine) and had a fatal outcome, with death occurring the same day. The cause of death was not reported. It is unknown if an autopsy was performed. The rechallenge was not applicable, as the event happened after the first dose. The benefit-risk relationship of mRNA-1273 (Moderna COVID-19 Vaccine) is not affected by this report.; Reported Cause(s) of Death: Unknown cause of death