probably a clot / had several clots in saphenous vein; pain in my calf; red / got really red; very painful; This spontaneous case was reported by a nurse and describes the occurrence of THROMBOSIS (probably a clot / had several clots in saphenous vein), PAIN IN EXTREMITY (pain in my calf), ERYTHEMA (red / got really red) and PAIN (very painful) in a 59-year-old female patient who received mRNA-1273 (Moderna COVID-19 Vaccine) for COVID-19 vaccination.     No medical history was provided by the reporter.  Concomitant products included DULAGLUTIDE (TRULICITY) and LOSARTAN for an unknown indication.    In December 2021, the patient received third dose of mRNA-1273 (Moderna COVID-19 Vaccine) (unknown route) 1 dosage form. In December 2021, the patient experienced THROMBOSIS (probably a clot / had several clots in saphenous vein) (seriousness criterion medically significant), PAIN IN EXTREMITY (pain in my calf) (seriousness criterion medically significant), ERYTHEMA (red / got really red) (seriousness criterion medically significant) and PAIN (very painful) (seriousness criterion medically significant). The patient was treated with ACETYLSALICYLIC ACID (ASPIRIN (E.C.)) ongoing since an unknown date for Adverse event, at an unspecified dose and frequency and ENOXAPARIN SODIUM (LOVENOX [ENOXAPARIN SODIUM]) for Adverse event, at an unspecified dose and frequency. At the time of the report, THROMBOSIS (probably a clot / had several clots in saphenous vein), PAIN IN EXTREMITY (pain in my calf), ERYTHEMA (red / got really red) and PAIN (very painful) outcome was unknown.      DIAGNOSTIC RESULTS (normal ranges are provided in parenthesis if available): On an unknown date, Blood test: had several clots in saphenous vein had several clots in saphenous vein.     For mRNA-1273 (Moderna COVID-19 Vaccine) (Unknown), the reporter did not provide any causality assessments.   On 12 Dec 2021, the patient went to emergency room for clot. The patient did a bunch of blood work and found she several clots in her saphenous vein. On 13 Dec 2021, the patient gone back to received venous treatment. The patient had no history of blood clots ever.  Company Comment: This RA case concerns 59 year old female  with no medical history reported, who experienced Serious ( Medically Significant ) , unexpected, AESI event of thrombosis  and other serious , unexpected events  of pain in extremity , erythema  and pain . These events  occurred  on Dec 2021 after vaccination with the 3rd dose of mRNA-1273 vaccine ( Moderna Covid 19 Vaccine ) .  This patient went to the ER re the possible blood clot . This patient did blood works and was found to have several blood clot in her saphenous  vein . She was treated with  Low molecular weight heparin Enoxaparin sodium  ( Lovenox)  and Aspirin .  The re-challenge for this case is not applicable since the events occurred after the 3rd dose and also the events outcome is unknown. The benefit -risk relationship of mRNA -1273 ( Moderna Covid 19 Vaccine) is not affected by this report.   This case was linked to MOD-2022-455792 (Patient Link).; Sender's Comments: This RA case concerns 59 year old female  with no medical history reported, who experienced Serious ( Medically Significant ) , unexpected, AESI event of thrombosis  and other serious , unexpected events  of pain in extremity , erythema  and pain . These events  occurred  on Dec 2021 after vaccination with the 3rd dose of mRNA-1273 vaccine ( Moderna Covid 19 Vaccine ) .  This patient went to the ER re the possible blood clot . This patient did blood works and was found to have several blood clot in her saphenous  vein . She was treated with  Low molecular weight heparin Enoxaparin sodium  ( Lovenox)  and Aspirin .  The re-challenge for this case is not applicable since the events occurred after the 3rd dose and also the events outcome is unknown. The benefit -risk relationship of mRNA -1273 ( Moderna Covid 19 Vaccine) is not affected by this report.