Saddle pulmonary embolism/ a large pulmonary embolism; Thought he had an allergy; Weakness; shortness of breath; With acute or pulmonale with Right ventricular dysfunction; Pain; Exhaustion; Functions unable to perform: walking and standing for a long period of time; Functions unable to perform: walking and standing for a long period of time; This is a spontaneous report received from contactable reporter(s) (Consumer or other non HCP). The reporter is the parent.  A 40 year-old male patient received bnt162b2 (BNT162B2), administration date 08Apr2021 (Batch/Lot number: unknown) at the age of 40 years as dose 2, single for covid-19 immunisation. The patient's relevant medical history and concomitant medications were not reported. Vaccination history included: Bnt162b2 (First dose), administration date: 11Mar2021, when the patient was 40 years old, for COVID-19 Immunization. The following information was reported: PULMONARY EMBOLISM (hospitalization, disability, life threatening) with onset 12May2021, outcome "not recovered", described as "Saddle pulmonary embolism/ a large pulmonary embolism"; HYPERSENSITIVITY (hospitalization, disability) with onset Apr2021, outcome "unknown", described as "Thought he had an allergy"; ASTHENIA (hospitalization, disability) with onset Apr2021, outcome "not recovered", described as "Weakness"; DYSPNOEA (hospitalization, disability) with onset Apr2021, outcome "not recovered", described as "shortness of breath"; RIGHT VENTRICULAR DYSFUNCTION (hospitalization, disability) with onset 2021, outcome "not recovered", described as "With acute or pulmonale with Right ventricular dysfunction"; PAIN (disability) with onset Oct2021, outcome "not recovered", described as "Pain"; FATIGUE (disability) with onset 2021, outcome "not recovered", described as "Exhaustion"; GAIT INABILITY (disability), DYSSTASIA (disability) all with onset 2021, outcome "not recovered" and all described as "Functions unable to perform: walking and standing for a long period of time". Patient received his first Pfizer vaccination on 11Mar2021 and his second on 08Apr2021 Soon thereafter, he developed progressive unexplained weakness and significant shortness of breath that forced him to stop whatever he was doing and to lie down to rest. He did not think much of it and thought he had an allergy, but he continued to experience physical deterioration. During the early morning of 12May2021, symptoms were so severe that he presented to an emergency room, There after examination, testing, and imaging, he was found to have a large pulmonary embolism, As a result, he was immediately treated with Xarelto. After being seen and examined, he was advised of the long process of treatment, his need to stay out of work, and he was referred to a pulmonologist. His treating pulmonologist concurred with patient diagnosis. In Jun2021 he described his condition as Saddle Pulmonary Emboli; a life-threatening pulmonary disorder, with right ventricular dysfunction. He opined that patient would need to remain on anti- coagulation therapy for at least one year, and will need to see a pulmonologist once a month. Doctor also added supplemental oxygen to his treatment. He estimated the beginning and ending dates for period of incapacity was 12May2021 to 12Aug2021. In Oct2021, five months from diagnosis, patient attempted to return to work on a five-hour, five day a week basis, but after one week he experienced ongoing symptoms of pain, weakness, and shortness of breath to the point of exhaustion. As such, patient returned to his pulmonologist who determined that his release of patient return to work was too aggressive. Doctor opined that his diagnosis was critical, would require a prolonged recovery time, and took pt out of work for an additional 30 day; 25Nov2021, when he would be evaluated again patient had appointment with Doctor on 08Dec2021. While it had not been specifically determined, patient and ' loved ones felt that he developed this pulmonary embolism as a direct result of the Pfizer vaccine. Probable duration of condition: 3 months. Patient was unable to perform any of his/her job functions due to the condition. Patient was unable to perform: walking and standing for a long period of time. Patient experienced saddle pulmonary emboli with acute or pulmonated with right ventricular dysfunction. will need to remain on anticoagulation therapy for at least one year. Patient was incapacitated for a single continuous period of time due to his/her medical condition, including any time for treatment and recovery, estimate the beginning and ending dates for the period of incapacity: 12May2021 to 12Aug2021. Patient had shortness of breath and oxygen dependency. He would require frequent monitoring he was now oxygen department. Doctor had followed him for the past 4 months that he was showing significant improvement, they would continue to closely follow his condition. He would need to remain on light duty and light activity, avoid all activities that can increase his heart rate or exert him being on a resting heart rate. The patient was hospitalized for pulmonary embolism, hypersensitivity, asthenia, dyspnoea, right ventricular dysfunction (start date: 12May2021, discharge date: 14May2021, hospitalization duration: 2 day(s)). The events "saddle pulmonary embolism/ a large pulmonary embolism", "thought he had an allergy", "weakness", "shortness of breath", "with acute or pulmonale with right ventricular dysfunction", "pain", "exhaustion", "functions unable to perform: walking and standing for a long period of time" and "functions unable to perform: walking and standing for a long period of time" were evaluated at the physician office visit and emergency room visit. The patient underwent the following laboratory tests and procedures: imaging procedure: (12May2021) have a large pulmonary embolism; investigation: (12May2021) have a large pulmonary embolism; (12May2021) have a large pulmonary embolism. Therapeutic measures were taken on 20May2021 as a result of pulmonary embolism, hypersensitivity, asthenia, dyspnoea, right ventricular dysfunction, pain, fatigue, gait inability, dysstasia. Patient was referred to other health care provider(s) cardiologist for evaluation or treatment.  The lot number for bnt162b2 was not provided and will be requested during follow up.