Blood cloth on left leg; Small pulmonary embolism in right lung; Headaches/grew more intense/Headaches continued after leaving the hospital/headaches got unmanageable and progressively worse up to September 2021/Went to ER several times because of the headaches/Headaches got better recently, but still ongoing; Couldn't see properly; Confusion; Not able to speak/ couldn't communicate; Not aware of location; This spontaneous case was reported by a consumer and describes the occurrence of THROMBOSIS (Blood cloth on left leg), PULMONARY EMBOLISM (Small pulmonary embolism in right lung) and HEADACHE (Headaches/grew more intense/Headaches continued after leaving the hospital/headaches got unmanageable and progressively worse up to September 2021/Went to ER several times because of the headaches/Headaches got better recently, but still ongoing) in a 47-year-old male patient who received mRNA-1273 (Moderna COVID-19 Vaccine) (batch nos. 047B21A and 019B21A) for COVID-19 vaccination. The occurrence of additional non-serious events is detailed below.     Concomitant products included CETIRIZINE HYDROCHLORIDE (ZYRTEC ALLERGY) for Allergy, ATORVASTATIN for Cholesterol.   On 29-Mar-2021, the patient received first dose of mRNA-1273 (Moderna COVID-19 Vaccine) (unknown route) 1 dosage form. On 26-Apr-2021, received second dose of mRNA-1273 (Moderna COVID-19 Vaccine) (unknown route) dosage was changed to 1 dosage form. On 29-Apr-2021, the patient experienced THROMBOSIS (Blood cloth on left leg) (seriousness criteria hospitalization and medically significant) and PULMONARY EMBOLISM (Small pulmonary embolism in right lung) (seriousness criteria hospitalization and medically significant). On an unknown date, the patient experienced HEADACHE (Headaches/grew more intense/Headaches continued after leaving the hospital/headaches got unmanageable and progressively worse up to September 2021/Went to ER several times because of the headaches/Headaches got better recently, but still ongoing) (seriousness criterion medically significant), VISUAL IMPAIRMENT (Couldn't see properly), CONFUSIONAL STATE (Confusion), SPEECH DISORDER (Not able to speak/ couldn't communicate) and DISORIENTATION (Not aware of location). The patient was hospitalized on 29-Apr-2021 due to PULMONARY EMBOLISM and THROMBOSIS. The patient was treated with HEPARIN for Clot blood, at a dose of 1 dosage form and APIXABAN (ELIQUIS) for Clot blood, at a dose of 1 dosage form. In September 2021, HEADACHE (Headaches/grew more intense/Headaches continued after leaving the hospital/headaches got unmanageable and progressively worse up to September 2021/Went to ER several times because of the headaches/Headaches got better recently, but still ongoing) had not resolved. At the time of the report, THROMBOSIS (Blood cloth on left leg), PULMONARY EMBOLISM (Small pulmonary embolism in right lung), VISUAL IMPAIRMENT (Couldn't see properly), CONFUSIONAL STATE (Confusion), SPEECH DISORDER (Not able to speak/ couldn't communicate) and DISORIENTATION (Not aware of location) outcome was unknown.      DIAGNOSTIC RESULTS (normal ranges are provided in parenthesis if available): On an unknown date, Antibody test: negative (Negative) negative. On an unknown date, Magnetic resonance imaging: abnormal (abnormal) follow MRI that white matter changed from the initial MRI and normal (normal) Normal. On an unknown date, Ultrasound testes: normal (normal) NORMAL.     For mRNA-1273 (Moderna COVID-19 Vaccine) (Unknown), the reporter did not provide any causality assessments.   Company Comment: This spontaneous case concerns a 47-year-old, male patient with no reported medical history, who experienced the unexpected, serious (hospitalized, medically significant) adverse events of special interest Thrombosis and Pulmonary embolism, and the unexpected, serious (medically significant) event of Headache. The events occurred on an unknown date after the second dose of mRNA-1273 vaccine. The patient started to experience leg cramps 2 days after vaccination. The discomfort was reported to have worsened after a day accompanied by soreness of left lower leg and was warm to touch. He sought consult at a hospital and was diagnosed with blood clot in the left leg and small pulmonary embolism in the right lung. He was admitted for 4-5 days where he was treated with blood thinner (heparin) for 3 days. On an unknown date after initial admission, the patient started experiencing persistent headaches and poor vision. Ultrasound and MRI conducted were reported to be normal. Heparin was then shifted to another blood thinner (Eliquis). The headaches continued to worsen and on repeat MRI, the patient was told that there were (unspecified) changes in the white matter. At this time, the patient was suffering from confusion, inability to speak and disorientation to place. He was prescribed with unspecified medications for the headache but the event was still increasing in intensity until 5 months post-vaccination. At the time of reporting, the headaches are ongoing. The outcome of the serious events are unknown. The benefit-risk relationship of mRNA-1273 is not affected by this report.; Sender's Comments: This spontaneous case concerns a 47-year-old, male patient with no reported medical history, who experienced the unexpected, serious (hospitalized, medically significant) adverse events of special interest Thrombosis and Pulmonary embolism, and the unexpected, serious (medically significant) event of Headache. The events occurred on an unknown date after the second dose of mRNA-1273 vaccine. The patient started to experience leg cramps 2 days after vaccination. The discomfort was reported to have worsened after a day accompanied by soreness of left lower leg and was warm to touch. He sought consult at a hospital and was diagnosed with blood clot in the left leg and small pulmonary embolism in the right lung. He was admitted for 4-5 days where he was treated with blood thinner (heparin) for 3 days. On an unknown date after initial admission, the patient started experiencing persistent headaches and poor vision. Ultrasound and MRI conducted were reported to be normal. Heparin was then shifted to another blood thinner (Eliquis). The headaches continued to worsen and on repeat MRI, the patient was told that there were (unspecified) changes in the white matter. At this time, the patient was suffering from confusion, inability to speak and disorientation to place. He was prescribed with unspecified medications for the headache but the event was still increasing in intensity until 5 months post-vaccination. At the time of reporting, the headaches are ongoing. The outcome of the serious events are unknown. The benefit-risk relationship of mRNA-1273 is not affected by this report.