Blood clot/ Right hand was numb from the right arm/ right arm was hurting; This spontaneous case was reported by a patient and describes the occurrence of THROMBOSIS (Blood clot/ Right hand was numb from the right arm/ right arm was hurting) in a 79-year-old female patient who received mRNA-1273 (Moderna COVID-19 Vaccine) for COVID-19 vaccination.     Patient did not ever have COVID positive test or diagnosis. The relating to mentioned and both acute and chronic illnesses at the time of vaccination.  Concurrent medical conditions included Penicillin allergy and Drug allergy.   In March 2021, the patient received dose of mRNA-1273 (Moderna COVID-19 Vaccine) (unknown route) 1 dosage form. In September 2021, received 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 (Blood clot/ Right hand was numb from the right arm/ right arm was hurting) (seriousness criteria hospitalization and medically significant). The patient was treated with WARFARIN for Clot blood, at an unspecified dose and frequency and Surgery (Surgery on 01 Sep 2021 for blood clot) for Thrombosis. At the time of the report, THROMBOSIS (Blood clot/ Right hand was numb from the right arm/ right arm was hurting) outcome was unknown.            Concomitant product use was not provided by the reporter.  Caller was calling to report her side effects to the Moderna vaccine.  It was stated patient started having side effect after taking the Moderna shot in Sept-2021. Patient had blood clot, so patient went to the neurologist. The neurologist sent her to the oncologist, and they did blood work. Patient been on Warfarin for years. After patient had the shot, they could not control her blood clot issues. Patient does not know other vaccines given within 1 month prior to Moderna COVID-19 vaccine.  Company Comment: This spontaneous case concerns a 79-year-old female patient, with no relevant medical history reported, who experienced the unexpected and serious (medically significant, hospitalization) event of Thrombosis. The patient received mRNA-1273 dose, not identifiable which dose of COVID-19 vaccination schedule it was however, it was reported that first booster vaccination took place approximately 6 months earlier. Temporal relationship with mRNA-1273 and potential latency cannot be assessed due to lack of exact dates of vaccination doses and event onset date. Patient described that despite warfarin therapy for many years the performed test results showed uncontrolled coagulation after vaccination. Event of thrombosis was accompanied by right arm numbness and pain. Treatment included surgical intervention to remove blood clots. No further clinical information or details about course of the event, its treatment, concurrent conditions with any accompanying circumstances and concomitant medication was provided for medical review. The outcome of the event was unknown at the time of the report. Additional information has been requested and report will be updated upon receipt of follow up information. The benefit-risk relationship of mRNA-1273 is not affected by this report.   This case was linked to MOD-2022-659394 (Patient Link). Sender's Comments: This spontaneous case concerns a 79-year-old female patient, with no relevant medical history reported, who experienced the unexpected and serious (medically significant, hospitalization) event of Thrombosis. The patient received mRNA-1273 dose, not identifiable which dose of COVID-19 vaccination schedule it was however, it was reported that first booster vaccination took place approximately 6 months earlier. Temporal relationship with mRNA-1273 and potential latency cannot be assessed due to lack of exact dates of vaccination doses and event onset date. Patient described that despite warfarin therapy for many years the performed test results showed uncontrolled coagulation after vaccination. Event of thrombosis was accompanied by right arm numbness and pain. Treatment included surgical intervention to remove blood clots. No further clinical information or details about course of the event, its treatment, concurrent conditions with any accompanying circumstances and concomitant medication was provided for medical review. The outcome of the event was unknown at the time of the report. Additional information has been requested and report will be updated upon receipt of follow up information. The benefit-risk relationship of mRNA-1273 is not affected by this report.