SARS-COV-2 TEST POSITIVE; SMEAR TEST; MALAISE; CHILLS; ASTHENIA; FATIGUE; PYREXIA; MYALGIA; ARTHRALGIA; THROMBOCYTOPENIA; AGEUSIA; ANOSMIA; ANTICOAGULANT THERAPY; BLOOD CREATININE NORMAL; BLOOD UREA INCREASED; COVID-19; CHEST X-RAY NORMAL; CONDITION AGGRAVATED; DECREASED APPETITE; DEHYDRATION; HAEMOGLOBIN NORMAL; LABORATORY TEST ABNORMAL; MENTAL STATUS CHANGES; PAIN; PLATELET COUNT DECREASED; PROCALCITONIN DECREASED; This spontaneous report received from a health care professional by a Regulatory Authority Vaccine Adverse Event Reporting System, concerned a 75 year old male of unspecified race and ethnic origin. The patient's height and weight were not reported. The patient's past medical history included: emphysema of lung, late onset alzheimer's disease, seizures, and sigmoid diverticulitis, and concurrent conditions included: adrenal adenoma left sided, arthritis, cholelithiasis, tear of right rotator cuff, tubular adenoma, thrombocytopenia, community acquired pneumonia, acute respiratory failure, hyponatremia, alcohol dependence, sepsis and moderate malnutrition. The patient denied any known medication allergies. The patient received covid-19 vaccine ad26.cov2.s (suspension for injection, intramuscular, batch number: 1805018, expiry: unknown) dose was not reported, 1 total administered to left arm on 10-MAR-2021 for an unspecified indication. Concomitant medications included donepezil hydrochloride for alzheimer's disease, levetiracetam for seizure, acetylsalicylic acid, azithromycin, cefdinir, and fluticasone propionate/salmeterol xinafoate. On 04-JAN-2022 (9 days ago), the patient started to have COVID-19 symptoms. He had been having progressive weakness (malaise) associated with body ache (pain), fever (pyrexia), chills, joint pain (arthralgia) and poor appetite (Decreased appetite) associated with altered mental status, loss of taste and smell (ageusia and anosmia) and asthenia. His blood urea (BUN) was 38 (Blood urea increased) and creatinine was 1 (Blood creatinine normal) and hemoglobin was 17 (Haemoglobin normal) and patient looked very dehydrated (Dehydration). Patient said that he had chest x-ray done at clinic and he had been told it looked okay (Chest X-ray normal). On 07-JAN-2022, he tested positive for COVID-19 (SARS-CoV-2 test positive). The patient had COVID-19 infection with progressive loss of appetite and seemed very dehydrated. He also had chills, muscle ache (myalgia), fatigue, joint pain and loss of taste and smell. Patient was not hypoxic and no steroids needed. His BUN was 44. The patient presented to the emergency room (ER) referred from clinic complaining of worsening COVID-19 symptoms (Condition aggravated) and abnormal lab results (Laboratory test abnormal). At the ER, patient was given intravenous (IV) fluid lactated Ringer bolus 1 L and Zofran 4 mg IV x1 and Tylenol 1000 mg oral x1 for progressive covid-19 infection. He looked very dehydrated clinically which improved with IV fluid hydration. His Procalcitonin was low (Procalcitonin decreased). The patient's platelet count decreased decreased (109 greater than 84 greater than 122 greater than 132) and he was diagnosed with thrombocytopenia. The patient was hospitalized (dates unspecified) for two days. Full barrier precautions were taken. Treatment medications included Tylenol and cough medication as needed. Anticoagulation with Lovenox subcutaneous per anticoagulation protocol was given (Anticoagulant therapy). Peripheral smear test was done, pending follow up on results with primary care physician. Patient was feeling better and felt comfortable and ready to discharge to home. He would follow-up closely with his own primary care physician. The action taken with covid-19 vaccine ad26.cov2.s was not applicable. The patient was recovering from ageusia, anosmia, anticoagulant therapy, arthralgia, asthenia, blood creatinine normal, blood urea increased, covid-19, chest x-ray normal, chills, condition aggravated, decreased appetite, dehydration, fatigue, haemoglobin normal, laboratory test abnormal, malaise, mental status changes, myalgia, pain, platelet count decreased, procalcitonin decreased, pyrexia, sars-cov-2 test positive, smear test, and thrombocytopenia. This report was serious (Hospitalization Caused / Prolonged). This case was associated with the Regulatory Authority: . The suspected product quality complaint has been confirmed to be the reported allegation was not confirmed and the root cause was determined to be not manufacturing related based on the RA evaluation/investigation performed.  Additional information received from the Regulatory Authority on 02-MAR-2022. The following information was updated and incorporated into the case narrative: Regulatory Authority investigation result.; Sender's Comments: V2: Follow up information in this version updated the RA investigation result. The follow up information does not change the causality of the previous reported events.  20220142098-covid-19 vaccine ad26.cov2.s- thrombocytopenia, platelet count decreased. 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  20220142098-covid-19 vaccine ad26.cov2.s- ageusia, anosmia, anticoagulant therapy, blood creatinine normal, blood urea increased, covid-19, chest x-ray normal, condition aggravated, decreased appetite, dehydration, haemoglobin normal, laboratory test abnormal, mental status changes, pain, procalcitonin decreased, sars-cov-2 test positive, smear test, malaise, chills, asthenia,  fatigue, pyrexia, myalgia. 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).  20220142098-covid-19 vaccine ad26.cov2.s- arthralgia. This event(s) is labeled per RA and is therefore considered potentially related.