saphenous thrombosis in the middle third of the leg.; this case was received (reference number: it-minisal02-840202) on 23-feb-2022 and was forwarded to moderna on 23-feb-2022. this regulatory authority case was reported by a consumer and describes the occurrence of thrombosis (saphenous thrombosis in the middle third of the leg.) in a 47-year-old male patient who received mrna-1273 (spikevax) (batch no. 094f21a) for covid-19 vaccination. no medical history information was reported. on 05-jan-2022, the patient received dose of mrna-1273 (spikevax) (intramuscular) .5 milliliter. on 11-jan-2022, after starting mrna-1273 (spikevax), the patient experienced thrombosis (saphenous thrombosis in the middle third of the leg.) (seriousness criterion hospitalization). at the time of the report, thrombosis (saphenous thrombosis in the middle third of the leg.) had resolved. it was reported that hypothyroidism treated with eutirox (5ml). no risk factors. no previous pathology. it was also reported that 07-feb-2022. insertion ecocolordoppler update warning information. company comment: this regulatory case concerns a 47-year-old male patient, with relevant medical history of hypothyroidism and bmi of 29.31 (overweight), experienced the unexpected serious aesi event, thrombosis, six days after a dose of mrna-1273. it was reported that the patient experienced saphenous thrombosis in the middle third of the leg and was hospitalized. at the time of reporting, the event had resolved. the patient's medical history of hypothyroidism and bmi of 29.31 (overweight) could be confounders to the event. the benefit-risk relationship of mrna-1273 is not affected by this report. event seriousness assessed as per regulatory authority reporting.; reporter's comments: hypothyroidism treated with eutirox (5ml) no risk factors. no previous pathology.; sender's comments: this regulatory case concerns a 47-year-old male patient, with relevant medical history of hypothyroidism and bmi of 29.31 (overweight), experienced the unexpected serious aesi event, thrombosis, six days after a dose of mrna-1273. it was reported that the patient experienced saphenous thrombosis in the middle third of the leg and was hospitalized. at the time of reporting, the event had resolved. the patient's medical history of hypothyroidism and bmi of 29.31 (overweight) could be confounders to the event. the benefit-risk relationship of mrna-1273 is not affected by this report. event seriousness assessed as per regulatory authority reporting