Clot has gone to her lungs; Mentally this has destroyed her; developed a blood clot; This spontaneous case was reported by a consumer and describes the occurrence of THROMBOSIS (developed a blood clot), PULMONARY EMBOLISM (Clot has gone to her lungs) and MENTAL DISORDER (Mentally this has destroyed her) in a 20-year-old female patient who received mRNA-1273 (Moderna COVID-19 Vaccine) for COVID-19 vaccination.     Previously administered products included for COVID-19 vaccination: Pfizer vaccination. Past adverse reactions to the above products included No adverse event with Pfizer vaccination.    On 09-Jan-2022, the patient received third dose of mRNA-1273 (Moderna COVID-19 Vaccine) (unknown route) 1 dosage form. On 11-Jan-2022, the patient experienced THROMBOSIS (developed a blood clot) (seriousness criteria hospitalization and medically significant). On an unknown date, the patient experienced PULMONARY EMBOLISM (Clot has gone to her lungs) (seriousness criteria hospitalization and medically significant) and MENTAL DISORDER (Mentally this has destroyed her) (seriousness criteria hospitalization and medically significant). The patient was hospitalized on 11-Jan-2021 due to PULMONARY EMBOLISM and THROMBOSIS, and then on 11-Jan-2022 due to MENTAL DISORDER. At the time of the report, THROMBOSIS (developed a blood clot), PULMONARY EMBOLISM (Clot has gone to her lungs) and MENTAL DISORDER (Mentally this has destroyed her) outcome was unknown.            Patient visited Emergency Room due to the event. She developed a blood clot on 11-Jan-2022, and went to the ER. She had a perfect health record and was physically fit. The blood clot was apparently big and serious, some of it had gone to her lungs, they would be performing surgery at the day of reporting and she will be in hospital for a week. She had no record of any health issues and had received Pfizer vaccination before,  perfectly healthy.   No Concomitant medications were reported. No treatment medications were reported. Company Comment: This is a spontaneous case concerning a 20-year-old, female patient with no medical history reported, with an Interchange of vaccine products (previous vaccination with TOZINAMERAN), who experienced the unexpected serious AESI event of Thrombosis with Pulmonary embolism. Thrombosis occurred approximately 2 days after the third dose of mRNA-1273 vaccine. She required hospitalization and a surgery was planned. The patient experienced a Mental disorder as a result. The benefit-risk relationship of mRNA-1273 vaccine is not affected by this report. Case was assessed as serious due to important medical event and hospitalization.; Sender's Comments: This is a spontaneous case concerning a 20-year-old, female patient with no medical history reported, with an Interchange of vaccine products (previous vaccination with TOZINAMERAN), who experienced the unexpected serious AESI event of Thrombosis with Pulmonary embolism. Thrombosis occurred approximately 2 days after the third dose of mRNA-1273 vaccine. She required hospitalization and a surgery was planned. The patient experienced a Mental disorder as a result. The benefit-risk relationship of mRNA-1273 vaccine is not affected by this report. Case was assessed as serious due to important medical event and hospitalization.