Patient died due to a massive blood clot on her lungs; Hot and cold; Patient had an uncomfortable day; Dizziness; This spontaneous case was reported by a consumer and describes the occurrence of PULMONARY THROMBOSIS (Patient died due to a massive blood clot on her lungs) in a 66-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 was provided by reporter.  Previously administered products included for Drug use for unknown indication: Pfizer covid-19 vaccine (1st dose, Batch number: EN6207) on 15-Mar-2021, Pfizer covid-19 vaccine (2nd dose and Batch number: EW0150) on 05-Apr-2021. Past adverse reactions to the above products included No adverse event with Pfizer covid-19 vaccine and Pfizer covid-19 vaccine. Concomitant products included CLOPIDOGREL BISULFATE (PLAVIX) for Anticoagulant therapy.    On 17-Nov-2021, the patient received third dose of mRNA-1273 (Moderna COVID-19 Vaccine) (unknown route) 1 dosage form. On 18-Nov-2021, the patient experienced FEELING OF BODY TEMPERATURE CHANGE (Hot and cold), DISCOMFORT (Patient had an uncomfortable day) and DIZZINESS (Dizziness). On 06-Dec-2021, the patient experienced PULMONARY THROMBOSIS (Patient died due to a massive blood clot on her lungs) (seriousness criteria death and medically significant). On 19-Nov-2021, FEELING OF BODY TEMPERATURE CHANGE (Hot and cold), DISCOMFORT (Patient had an uncomfortable day) and DIZZINESS (Dizziness) had resolved. The patient died on 06-Dec-2021. The reported cause of death was patient died due to a massive blood clot on her lungs. It is unknown if an autopsy was performed.            No treatment information was provided. Husband mentioned that previous to the administration of the booster to his wife, there where warning signs to not to get the Moderna vaccine, and to get a stronger blood thinner first. The reporter stated he would consult the case with a lawyer.  Company Comment- This is a fatal case that concerns a 66-year-old female patient with no medical history, who experienced the unexpected serious adverse event of special interest, Pulmonary Thrombosis. The event was medically significant and caused the sudden demise of the patient. The event occurred in 20 days after receiving the third dose of mRNA-1273 Vaccine. The patient died on 06-Dec-2021. The reported cause of death was patient died due to a massive blood clot on her lungs. It is unknown if an autopsy was performed. The benefit-risk relationship of mRNA-1273 Vaccine is not affected by this report.   Reporter did not allow further contact; Sender's Comments: This is a fatal case that concerns a 66-year-old female patient with no medical history, who experienced the unexpected serious adverse event of special interest, Pulmonary Thrombosis. The event was medically significant and caused the sudden demise of the patient. The event occurred in 20 days after receiving the third dose of mRNA-1273 Vaccine. The patient died on 06-Dec-2021. The reported cause of death was patient died due to a massive blood clot on her lungs. It is unknown if an autopsy was performed. The benefit-risk relationship of mRNA-1273 Vaccine is not affected by this report.; Reported Cause(s) of Death: Patient died due to a massive blood clot on her lungs