ADVERSE EFFECT OF VACCINE; SHORTNESS OF BREATH; FATIGUE; HEADACHE; LOW PLATELETS; NIGHT SWEATS; DIAPHORESIS; BLURRED VISION; FEVER; BODY ACHES; This spontaneous report was received from a physician via a company representative and concerned a  white nonhispanic or Latino 50 year old male. Initial information was received on 28-APR-2021, with additional information obtained via telephone follow up from a physician on 29-APR-2021. The patient's height was 73 inches and weighed 252 lbs; approximate body mass index was 32.68 kg/m2. Medical history included: lung infection in 2014 which led to aortic valve disease which required biologic aortic valve replacement (2014); prolapse of right coronary aortic vale cusp, severe aortic insufficiency. There was no history of hyperlipidemia and was positive for family history of cardiovascular disease. Concurrent conditions included attention deficit disorder (ADD), back and neck problem, other congenital anomaly of heart, hypertension, lumbago, shortness of breath and thyroid nodule. The patient received COVID-19 vaccine Ad26.CoV2.S (suspension for injection, intramuscular, batch number and expiry date unknown) on 19-MAR-2021 for prophylactic vaccination. The batch number was not reported and has been requested. Concomitant medications included: carvedilol, losartan and atorvastatin (all for aortic valve replacement).  Also aspirin, Adderall (dextroamphetamine-amphetamine) both for unspecified indication. On 20-MAR-2021, the day after receiving the vaccine, the patient developed fevers, body aches and headache which resolved within 24 hours. Then a week on an unspecified date, he developed more symptoms which included fatigue, shortness of breath for the most part and some headaches. On 27-MAR-2021 the patient experienced a single episode of visual disturbance of burred vision while driving. At a stoplight vision in both eyes were blurred and he had trouble see the road; he no longer could drive. The blurred vision resolved within a few minutes and not vertigo or headache occurred at that time; and there were no other reported visual changes.  The patient visited his physician 28 days after receiving the vaccine on 16-APR-2021. He reported ongoing fatigue, body aches and headaches. No further visual changes or disturbances. He felt fatigue and shortness of breath were the most noticeable. He denied chest pains and fevers but has been experiencing night sweats (unspecified start date); and generally feels unwell and described himself as "feeling off". No leg edema or leg pain currently. Also no coughing, wheezing or bruising. His concentration was stable and there was no loss of memory. No other neurological symptoms. Physical exam was positive for chills diaphoresis, fatigue, fever and shortness of breath; cardiovascular examine revealed a murmur present, and pulmonary examine was normal breath sounds, no decreased breath sounds, wheezing, rhonchi or rates. Vital signs: blood pressure 104/68, pulse 93, temperature 98. The physician's assessment also included an adverse effect of vaccine. Laboratory results form 16-APR-2021 included: Creatinine (normal range 0.50 - 130 mg/dl) 1.09, white blood count (WBC) (normal range 3.8 - 10.8) 3.4, red blood cell count (RBC) (normal range 4.20 -5.8) 4.92, hemoglobin (normal range 13.2-17.1 g/DL) 13.9, glucose (normal range 71-99mg/dL)109, D-Dimer elevated at 286 (normal range <230), elevated C-Reactive Protein (CRP) (normal range 0 - 5 mg/L) 32.3, fibrinogen (results not reported), Covid-19 Antigen Antibody negative, platelet count 123,000 (lower limit of normal <140,000). The patient has a baseline platelet count of 200,000 from JAN-2021 and for the past 9 years had ranged from 180,000 - 240,000. A heparin-induced thrombocytopenia (HIT) was negative anti-PF4 antibody. On 20-APR-2021, the patient received Computerized tomogram (CT) of the head with and without contrast which was normal - no acute hemorrhage, mass effect or abnormal enhancement. The patient also had a CT chest with contrast with no evidence of pulmonary embolism to the segmental level; a 16 by 16 mm nodule with small calcification was noted, this was nonspecific but could reflect primary lung cancer, correlation with PET/CT is indicated. Additional laboratory results on 20-APR-2021 concerning serotonin release stated as follows: Positive, 6%, 40%, 37%. HIT panel negative with less than 0.6  antibody On 27-APR-2021 additional laboratory results were as follows: WBC 4.1, RBC 4.95, hemoglobin 14.0 g/dL, D-Dimer 275, fibrinogen 427 and HIT panel negative with less than 0.6  antibody. A hematologist was consulted and a complete blood count and HIT panel were performed on 28-APR-2021. Results were platelet count of 159,000, D Dimer of 275, HIT negative anti-PF4 antibody screen and the SRA assay was pending. On 29-APR-2021 the duplex of left lower extremity was negative for deep vein thrombosis (DVT). Additional laboratory reports included a platelet factor 4 antibody test test methodology which used latex particle enhanced immunoassay to detect anti -pF4/heparin antibodies (reference range 0.0-9), with the patient's value was <0.6 (negative). A COVID PCR test was not performed. An enzyme-linked immunosorbent assay (ELISA) test was ordered for 30-APR-2021 for anti-PF4 antibodies.  The action taken with COVID-19 vaccine Ad26.CoV2.S was not applicable. The outcome of the event blurred vision and fever were resolved;  the outcome of low platelets, adverse event of vaccine, shortness of breath, fatigue, headache, body aches, night sweats and diaphoresis were not reported. This report was serious (other medically important condition).; Sender's Comments: V0.20210456790-COVID-19 vaccine Ad26.CoV2.S -Low platelet counts,blurred vision,adverse affect of vaccination. This event(s) is considered unassessable. The event(s) has a compatible/suggestive temporal relationship, is unlabeled, and has unknown scientific plausibility. There is no information on any other factors potentially associated with the event(s).