leg was swollen, pinkish, swollen compared other leg, blood clot from ankle, up the leg to groin, Long blood clot; This spontaneous case was reported by a patient and describes the occurrence of THROMBOSIS (leg was swollen, pinkish, swollen compared other leg, blood clot from ankle, up the leg to groin, Long blood clot) in a 76-year-old female patient who received mRNA-1273 (Moderna COVID-19 Vaccine) (batch nos. 076C21A, 020A21A, 028L20A and 005M21A) for COVID-19 vaccination.     The patient had never been diagnosed with/ tested positive for COVID-19. Patient did not have any acute illness at the time of vaccination and up to one month before. Patient did not received any other vaccine within 1 month prior to Moderna COVID-19 vaccine.  The patient's past medical history included Clot blood (previously had a clot years ago) and Abdominal operation (at 35 yrs old). Previously administered products included for Clot blood: Coumadin (it went away after 6 months.) and WARFARIN (it went away after 6 months.). Past adverse reactions to the above products included No adverse event with Coumadin and WARFARIN. Concurrent medical conditions included Penicillin allergy and Sulfonamide allergy (Sulfur drugs).   On 31-Jan-2021, the patient received first dose of mRNA-1273 (Moderna COVID-19 Vaccine) (Intramuscular) .5 milliliter. On 01-Mar-2021, received second dose of mRNA-1273 (Moderna COVID-19 Vaccine) (unknown route) dosage was changed to .5 milliliter. On 22-Oct-2021, received dose of mRNA-1273 (Moderna COVID-19 Vaccine) (unknown route) dosage was changed to 1 dosage form. On 11-Apr-2022, received dose of mRNA-1273 (Moderna COVID-19 Vaccine) (unknown route) dosage was changed to 1 dosage form. On 10-Dec-2021,  after starting mRNA-1273 (Moderna COVID-19 Vaccine), the patient experienced THROMBOSIS (leg was swollen, pinkish, swollen compared other leg, blood clot from ankle, up the leg to groin, Long blood clot) (seriousness criterion medically significant). The patient was treated with APIXABAN (ELIQUIS) for Anticoagulant therapy, at a dose of 5 milligram and APIXABAN (ELIQUIS) ongoing since an unknown date for Anticoagulant therapy, at a dose of 2.5 milligram. At the time of the report, THROMBOSIS (leg was swollen, pinkish, swollen compared other leg, blood clot from ankle, up the leg to groin, Long blood clot) outcome was unknown.            The patient had received second booster dose of Moderna vaccine on 11Apr2022 with batch number 005M21A. On 10 Dec2021 patient seek medical care. Patient had experienced a similar event in the past at 35 yrs old after abdominal surgery and was on Warfarin and then Coumadin and it went away after 6 months.  Patient had residual effects and was on 5 mg of Eliquis and now on 2.5 mg.   It was reported that patient received all Moderna vaccines 2 primary and 2 Booster and developed a blood clot in 10 Dec 2021. Patient does not think that would be taking the new one because patient was on blood thinners.  HCP did not think the blood clot was due to the vaccine. Patient said previously had a clot years ago but not as extreme as this one, may have to be on the medication for the rest of her life.  Company comment: This is a spontaneous case concerning a 76-year-old, female patient with relevant medical history of blood clot after abdominal surgery. The patient has vaccination history of receiving first and second dose of mRNA-1273. The patient experienced the unexpected serious (medically significant) AESI event of thrombosis. The event occurred approximately 49 days after the third dose (first booster) of mRNA-1273 vaccine administration. Allegedly the event was described as, the patient woke up with pinkish swollen leg compared to other leg. It was reported that that the patient experienced blood clot from ankle, up to the leg and to the groin. The patient sought medical consult and was given Apixaban (Eliquis) 5 mg and now on 2.5 mg. It was reported that the health care practitioner does not think that the blood clot was due to the vaccine. The patient's age and medical history of blood clot remain confounders for the event thrombosis. The benefit-risk relationship of mRNA-1273 vaccine is not affected by this report.; Sender's Comments: This is a spontaneous case concerning a 76-year-old, female patient with relevant medical history of blood clot after abdominal surgery. The patient has vaccination history of receiving first and second dose of mRNA-1273. The patient experienced the unexpected serious (medically significant) AESI event of thrombosis. The event occurred approximately 49 days after the third dose (first booster) of mRNA-1273 vaccine administration. Allegedly the event was described as, the patient woke up with pinkish swollen leg compared to other leg. It was reported that that the patient experienced blood clot from ankle, up to the leg and to the groin. The patient sought medical consult and was given Apixaban (Eliquis) 5 mg and now on 2.5 mg. It was reported that the health care practitioner does not think that the blood clot was due to the vaccine. The patient's age and medical history of blood clot remain confounders for the event thrombosis. The benefit-risk relationship of mRNA-1273 vaccine is not affected by this report.