the patient died in the autopsy results was lung blood clots whitish, not reddish; high blood pressure; heart palpitations; could not taste anything; trouble breathing; Veins popped up; This spontaneous case was reported by a consumer and describes the occurrence of THROMBOSIS (the patient died in the autopsy results was lung blood clots whitish, not reddish) in a patient of an unknown age and gender who received mRNA-1273.815 (SPIKEVAX 2023-2024) for COVID-19 prophylaxis. The occurrence of additional non-serious events is detailed below.     No Medical History information was reported.    On an unknown date, the patient received dose of mRNA-1273.815 (SPIKEVAX 2023-2024) (unknown route) 1 dosage form. On an unknown date, the patient experienced THROMBOSIS (the patient died in the autopsy results was lung blood clots whitish, not reddish) (seriousness criteria death and medically significant), HYPERTENSION (high blood pressure), PALPITATIONS (heart palpitations), AGEUSIA (could not taste anything), DYSPNOEA (trouble breathing) and VARICOSE VEIN (Veins popped up). The patient died on an unknown date. An autopsy was performed. The autopsy-determined cause of death was lung blood clots whitish. At the time of death, HYPERTENSION (high blood pressure), PALPITATIONS (heart palpitations), AGEUSIA (could not taste anything), DYSPNOEA (trouble breathing) and VARICOSE VEIN (Veins popped up) outcome was unknown.      DIAGNOSTIC RESULTS (normal ranges are provided in parenthesis if available): On an unknown date, Blood pressure measurement: High.     For mRNA-1273.815 (SPIKEVAX 2023-2024) (Unknown), the reporter did not provide any causality assessments.   No relevant concomitant medications were reported.  Patient experienced the same symptoms as that of the patient's neighbor and died and the autopsy results found lung blood clots whitish, not reddish, which pointed out a protein-based blood clot and not red blood cell blood clots.   No treatment medications were reported.  Company comment This spontaneous case concerns a patient of an unknown age and gender with no medical history reported, who experienced the unexpected, serious (medically significant and fatal), event of thrombosis (AESI), that occurred on an unknown date in the context of a dose of mRNA-1273.815 (SPIKEVAX 2023-2024). It was reported that the patient experienced same symptoms as the reporter: symptoms 1 hour after the vaccine was given: palpitations, trouble breathing, blood clots that were very bad at the beginning, very long and the veins popped up. A few days later, the reporter could not taste anything, a few times later, developed high blood pressure. Reporter still had high blood pressure that worsened a few days ago. Additionally, the patient died on an unknown date. An autopsy was performed. The autopsy-determined cause of death was lung blood clots whitish. The benefit-risk relationship of dose of mRNA-1273.815 (SPIKEVAX 2023-2024) vaccine is not affected by this report.   This case was linked to US-MODERNATX, INC.-MOD-2021-101786 (E2B Linked Report).; Sender's Comments:  US-MODERNATX, INC.-MOD-2021-101786:Patient 2; Autopsy-determined Cause(s) of Death: lung blood clots whitish