Pulmonary embolism; Deep vein thrombosis; COVID-19; received COVID-19 vaccine ad26.cov.2; This spontaneous case was reported by an other health care professional and describes the occurrence of PULMONARY EMBOLISM (Pulmonary embolism), DEEP VEIN THROMBOSIS (Deep vein thrombosis) and COVID-19 (COVID-19) in a 69-year-old male patient who received mRNA-1273 (Moderna COVID-19 Vaccine) (batch no. 0091D21A) for an unknown indication. The occurrence of additional non-serious events is detailed below.    Co-suspect product included non-company product COVID-19 VACCINE NRVV AD26 (JNJ 78436735) (JANSSEN COVID-19 VACCINE) for an unknown indication.    No Medical History information was reported.   On 05-Mar-2021, the patient received first dose of COVID-19 VACCINE NRVV AD26 (JNJ 78436735) (JANSSEN COVID-19 VACCINE) (Intramuscular) 1 dosage form. On 22-Nov-2021, the patient received second dose of mRNA-1273 (Moderna COVID-19 Vaccine) (Intramuscular) 1 dosage form. On 27-Jan-2022, the patient experienced PULMONARY EMBOLISM (Pulmonary embolism) (seriousness criteria hospitalization and medically significant), DEEP VEIN THROMBOSIS (Deep vein thrombosis) (seriousness criteria hospitalization and medically significant) and COVID-19 (COVID-19) (seriousness criterion hospitalization). On an unknown date, the patient experienced INTERCHANGE OF VACCINE PRODUCTS (received COVID-19 vaccine ad26.cov.2). The patient was hospitalized for 2 days due to COVID-19, DEEP VEIN THROMBOSIS and PULMONARY EMBOLISM. At the time of the report, PULMONARY EMBOLISM (Pulmonary embolism), DEEP VEIN THROMBOSIS (Deep vein thrombosis), COVID-19 (COVID-19) and INTERCHANGE OF VACCINE PRODUCTS (received COVID-19 vaccine ad26.cov.2) outcome was unknown.        For mRNA-1273 (Moderna COVID-19 Vaccine) (Intramuscular), the reporter did not provide any causality assessments.   No concomitant medications were reported.  It was unknown whether patient had any adverse events following vaccination with first dose of Janssen vaccine.  The patient additionally received booster non company suspect vaccine included Moderna (dose number in series 2) on 22-Nov-2021. On unspecified date patient was hospitalized for 2 days.  No treatment medication was provided.  This case was received to Janssen via VAERS (2071686).  Company comment: This case concerns a 69-year-old male patient with medical history of interchange of vaccine products, who experienced the unexpected, serious (hospitalization and medically significant) events of pulmonary embolism, deep vein thrombosis, and COVID-19 2 months after the booster dose of mRNA-1273. The medical history of interchange of vaccine products (ad26.cov.2 COVID-19 vaccine), as well as concomitant COVID-19 infection, are confounding factors for deep vein thrombosis and pulmonary embolism. Outcome was reported as unknown. Information regarding clinical evaluation, diagnostic tests and treatment provided has not been disclosed. The benefit-risk relationship of mRNA-1273 is not affected by this report.; Reporter's Comments: The events have a compatible/ suggestive temporal relationship, is unlabeled, and has unknown scientific plausibility. there is no information on any other factors potentially associated with the events. Therefore, this events considered un-assessable.; Sender's Comments: This case concerns a 69-year-old male patient with medical history of interchange of vaccine products, who experienced the unexpected, serious (hospitalization and medically significant) events of pulmonary embolism, deep vein thrombosis, and COVID-19 2 months after the booster dose of mRNA-1273. The medical history of interchange of vaccine products (ad26.cov.2 COVID-19 vaccine), as well as concomitant COVID-19 infection, are confounding factors for deep vein thrombosis and pulmonary embolism. Outcome was reported as unknown. Information regarding clinical evaluation, diagnostic tests and treatment provided has not been disclosed. The benefit-risk relationship of mRNA-1273 is not affected by this report.