UNABLE TO URINATE AT ALL; BLOOD CLOTS THAT WERE BLOCKING CATHETER; PROSTATE INFLAMMATION/ ENLARGED PROSTATE; This spontaneous report received from a consumer concerned a 71 year old male. The patient's weight was 212 pounds, and height was 182 centimeters. The patient's past medical history included urinary tract infection (UTI), enlarged prostate,. The patient's past medication included shingles vaccine for alpha gal syndrome. Concurrent conditions included kidney stones, alcohol user, non smoker, polyethylene glycol allergy, sulfa allergy, alpha gal syndrome and high uric acid. The patient previously experienced drug allergy when treated with polyethylene glycol for unspecified indication.The patient had no illness at the time of vaccination, no history of drug abuse. Because of the inflammation the stones caused when in the process of being passed, the patient also had occasional issues with an enlarged prostate as well as UTIs as a result of the stones. However, the patient never had his prostate enlarged to the point where he could not urinate as a result of passing stone. The patient has passed a small stone unannounced without symptoms approximately 10 days prior to receiving the COVID vaccine. The patient had no side effects after passing the stone, there was no pain, no dis colouration and no trouble urinating. The patient felt 100% with no after effects that would be attributed to passing the small stone. The patient received COVID-19 vaccine ad26.cov2.s (suspension for injection, route of admin not reported, batch number: 1805029, and 1805029 expiry: not reported) dose was not reported, administered on 09-MAR-2021 09:30 in left deltoid for prophylactic vaccination. Expiry date was not reported and has been requested. Concomitant medications included allopurinol for high uric acid, and prevention of stones On 10-MAR-2021, 1:00 AM, approximately 15 hours post vaccination the patient experienced pain and trouble urinating. Subsequently, the patient went to urgent care where he was diagnosed with enlarged prostate and sent home. By mid morning, he was unable to urinate at all and went to see the physician. Patient has undergone a bladder scan and catheter was placed. On 10-MAR-2021 01:00, the patient also experienced prostate inflammation/ enlarged prostate On 13-Mar-2021, the patient returned to the emergency room twice for blood clots that were blocking the catheter due to overextension of the bladder.  On 18-Mar-2021, the patient returned to the physician, got the catheter removed and scope was performed. The patient was noted to have greatly enlarged prostate gland and the physician allowed him to leave the office without catheter. Several hours later, the patient was unable to urinate once again and went to physician's office and the catheter was put back in for additional two weeks, at the end of that time the patient will be reassessed.  Laboratory data included: Prostate examination (NR: not provided) Enlarged prostate.  On 18-MAR-2021, Laboratory data included: Ureteroscopy (NR: not provided) prostate greatly enlarged. Treatment medications (dates unspecified) included: finasteride to help with urine flow. The action taken with COVID-19 vaccine ad26.cov2.s was not applicable. The patient was recovering from prostate inflammation/ enlarged prostate, had not recovered from unable to urinate at all, and the outcome of blood clots that were blocking catheter was not reported. This report was serious (Other Medically Important Condition)  Additional information was received from consumer on 31-MAR-2021 following information was updated and incorporated into case narrative: Patient demographic details (height, weight, date of birth), patient's past medical history ( urinary tract infection (UTI), enlarged prostate), past medication (shingles vaccine for alpha gal syndrome), concurrent conditions (kidney stones, alcohol user, non smoker, polyethylene glycol allergy, sulfa allergy, alpha gal syndrome and high uric acid), COVID-19 vaccine therapy details (vaccination time), additional event of enlarged prostate, reporter details, lab details were added.; Sender's Comments: V2.  Follow up information received regarding Patient demographic details, past medical history, past medication, concurrent conditions, vaccine therapy details, additional events , reporter details, lab details were added . 20210323574-COVID-19 VACCINE AD26.COV2.S- Unable to urinate at all, Prostate inflammation. Follow-up received regarding Clinical Details. This event(s) is considered not related. The event(s) has a compatible/suggestive temporal relationship, is unlabeled, and has unknown scientific plausibility. There are other factors more likely to be associated with the event(s) than the drug. Specifically: MEDICAL HISTORY, UNDERLYING DISEASE .