2 weeks ago they were diagnosed with a blood clot in their right leg; not feeling all that great; vein on their right leg above their knee was hard and purple; a massive swelling on their right leg; This spontaneous case was reported by a consumer and describes the occurrence of THROMBOSIS (2 weeks ago they were diagnosed with a blood clot in their right leg) in a 65-year-old female patient who received mRNA-1273 (Moderna COVID-19 Vaccine) (batch nos. 003A21A and 031L20A) for COVID-19 vaccination. The occurrence of additional non-serious events is detailed below.     No Medical History information was reported.   On 13-Feb-2021, the patient received first dose of mRNA-1273 (Moderna COVID-19 Vaccine) (unknown route) 1 dosage form. On 11-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 THROMBOSIS (2 weeks ago they were diagnosed with a blood clot in their right leg) (seriousness criterion medically significant), MALAISE (not feeling all that great), VEIN DISORDER (vein on their right leg above their knee was hard and purple) and PERIPHERAL SWELLING (a massive swelling on their right leg). At the time of the report, THROMBOSIS (2 weeks ago they were diagnosed with a blood clot in their right leg), MALAISE (not feeling all that great), VEIN DISORDER (vein on their right leg above their knee was hard and purple) and PERIPHERAL SWELLING (a massive swelling on their right leg) outcome was unknown.            Patient was reported  that 2 weeks ago they were diagnosed with a blood clot in their right leg. They were not feeling all that great and then they fell and noticed a vein on their right leg above their knee was hard and purple and they were having a massive swelling on their right leg, so they went to a HCP, vein specialist, who prescribe they take daily shots of blood thinners for 6 weeks. Patient states 20 years ago they had DBT. Patient state they do not take any medication regularly.  No concomitant medications were provided.  Company Comment:  This case concerns a 65 year old female patient with no relevant medical history who was diagnosed with a blood clot in her right leg (thrombosis) (serious unexpected event). The patient additionally experienced non-serious events of malaise, vein disorder, and peripheral swelling (right leg swelling). The events occurred after an unknown duration of administration of mRNA-1273. The benefit-risk relationship of mRNA-1273 is not affected by this report.   This case was linked to US-MODERNATX, INC.-MOD-2021-317609, US-MODERNATX, INC.-MOD-2021-317542 (E2B Linked Report).; Sender's Comments: This case concerns a 65 year old female patient with no relevant medical history who was diagnosed with a blood clot in her right leg (thrombosis) (serious unexpected event). The patient additionally experienced non-serious events of malaise, vein disorder, and peripheral swelling (right leg swelling). The events occurred after an unknown duration of administration of mRNA-1273. The benefit-risk relationship of mRNA-1273 is not affected by this report. US-MODERNATX, INC.-MOD-2021-317542: US-MODERNATX, INC.-MOD-2021-317609:Same reporter and Patient but different event