massive blood clots in his left lung; 2 clots in his right leg; coughing; he couldn't catch his breath; chest pains on the left side; Cannot get the second dose; This spontaneous case was reported by a consumer and describes the occurrence of PULMONARY THROMBOSIS (massive blood clots in his left lung), DEEP VEIN THROMBOSIS (2 clots in his right leg), COUGH (coughing), DYSPNOEA (he couldn't catch his breath) and CHEST PAIN (chest pains on the left side) in a 76-year-old male patient who received mRNA-1273 (Moderna COVID-19 Vaccine) (batch no. 013L20A) for COVID-19 vaccination. The occurrence of additional non-serious events is detailed below.     The patient's past medical history included Pacemaker insertion (cardiac). Family history included Clot blood (Blood clots run in his family. He has a spot on his lung that was confirmed as not cancer).    On 22-Jan-2021, the patient received first dose of mRNA-1273 (Moderna COVID-19 Vaccine) (Intramuscular) 1 dosage form. On 30-Jan-2021, the patient experienced PULMONARY THROMBOSIS (massive blood clots in his left lung) (seriousness criteria hospitalization and medically significant), DEEP VEIN THROMBOSIS (2 clots in his right leg) (seriousness criteria hospitalization and medically significant), COUGH (coughing) (seriousness criterion hospitalization), DYSPNOEA (he couldn't catch his breath) (seriousness criterion hospitalization) and CHEST PAIN (chest pains on the left side) (seriousness criterion hospitalization). On an unknown date, the patient experienced PRODUCT DOSE OMISSION ISSUE (Cannot get the second dose). The patient was hospitalized from 08-Feb-2021 to sometime in February 2021 due to CHEST PAIN, COUGH, DEEP VEIN THROMBOSIS, DYSPNOEA and PULMONARY THROMBOSIS. The patient was treated with APIXABAN (ELIQUIS) for Adverse event, at a dose of 5 milligram twice a day; ALBUTEROL [SALBUTAMOL] for Adverse event, at an unspecified dose and frequency; TIOTROPIUM BROMIDE MONOHYDRATE (SPIRIVA) for Adverse event, at an unspecified dose and frequency; OXYGEN for Adverse event, at a dose of 2 liters 24/7 and Surgery (Clots in lungs were surgically removed (Pulmonary thrombectomy)) for Pulmonary thrombosis. On 08-Feb-2021, COUGH (coughing), DYSPNOEA (he couldn't catch his breath) and CHEST PAIN (chest pains on the left side) had resolved. At the time of the report, PULMONARY THROMBOSIS (massive blood clots in his left lung), DEEP VEIN THROMBOSIS (2 clots in his right leg) and PRODUCT DOSE OMISSION ISSUE (Cannot get the second dose) outcome was unknown.      DIAGNOSTIC RESULTS (normal ranges are provided in parenthesis if available): On 30-Jan-2021, Heart rate: high (High) increased. On 30-Jan-2021, Oxygen saturation: 93% (Low) 93%.     The action taken with mRNA-1273 (Moderna COVID-19 Vaccine) (Intramuscular) was unknown.       Concomitant product use was not provided by the reporter.  Based on the current available information and temporal association between the use of the product and the start date of the serious unexpected events of Pulmonary thrombosis and Deep vein thrombosis, a causal relationship between the events and mRNA-1273 cannot be excluded. Case causality is confounded by increased risk of thrombosis due to the history of pacemaker complicated by advanced age and family history. Further information has been requested.   Most recent FOLLOW-UP information incorporated above includes: On 13-Aug-2021: Follow up has no significant information On 13-Aug-2021: Follow up received and a new event of Dose omission was added.; Sender's Comments: Based on the current available information and temporal association between the use of the product and the start date of the serious unexpected events of Pulmonary thrombosis and Deep vein thrombosis, a causal relationship between the events and mRNA-1273 cannot be excluded. Case causality is confounded by increased risk of thrombosis due to the history of pacemaker complicated by advanced age and family history. Further information has been requested.