EMBOLIC STROKE; ISCHAEMIC STROKE; COVID-19 PNEUMONIA; DELIRIUM; DEPRESSED LEVEL OF CONSCIOUSNESS; ENCEPHALOPATHY; THALAMIC INFARCTION; UNRESPONSIVE TO STIMULI; SYNCOPE; COVID-19; SARS-COV-2 TEST POSITIVE; COUGH; AGITATION; CONFUSIONAL STATE; DYSPNOEA; HYPERSOMNIA; HYPOPHAGIA; HEADACHE; ANTICOAGULANT THERAPY; GASTROINTESTINAL TUBE INSERTION; BLOOD FOLATE NORMAL; BLOOD THYROID STIMULATING HORMONE DECREASED; VITAMIN B12 NORMAL; GLYCOSYLATED HAEMOGLOBIN NORMAL; URINE ANALYSIS NORMAL; COMPUTERISED TOMOGRAM HEAD ABNORMAL; DRUG SCREEN NEGATIVE; COMPUTERISED TOMOGRAM; MAGNETIC RESONANCE IMAGING HEAD; CHEST X-RAY ABNORMAL; FATIGUE; ASTHENIA; LETHARGY; PATIENT RESTRAINT; SOMNOLENCE; FALL; HEAD INJURY; HAEMATURIA; INCONTINENCE; TREMOR; URINARY TRACT INFECTION; CONFIRMED CLINICAL VACCINATION FAILURE; This spontaneous report received from a health care professional by a Regulatory Authority Vaccine Adverse Event Reporting System (VAERS) (VAERS ID: 1949212) and concerned a 69 years old female of an unspecified race and ethnic origin. The patient's height, and weight were not reported. The patient's past medical history included: bruxism, des (Diethylstilbestrol) exposure in utero, heart attack (date unknown), lateral myocardial infarction (in 2001 - minimal coronary disease, for medical treatment), atrial fibrillation (in 2012) treated with Xarelto (rivaroxaban) and bariatric surgery. Concurrent conditions included: heart failure (2008); non-insulin dependent diabetes mellitus type 2 without retinopathy, and myocardial infarct (25-JUL-2012); low serum iron (NR: not provided) (28-OCT-2013); coronary artery disease (12-JUN-2014) involving native coronary artery of native heart without angina pectoris, smoker (tobacco use presenting hazards to health); senile nuclear cataract bilateral and myopia of both eyes (22-MAR-2017); bilateral carotid artery disease (CAD) (19-JUL-2017), 50-69% predicted stenosis right internal carotid artery (RICA) and less than 50 % stenosis of the left internal carotid artery (LICA) (as per carotid doppler done on 16-AUG-2017); mild asymmetric left ventricular hypertrophy (LVH) [echocardiogram (ECHO) done on 16-AUG-2018 showed ejection fraction (EF) 71 % with mild asymmetric LVH but no echo findings of outflow tract obstruction and there was no significant valve pathology]; right breast cancer (15-MAR-2021) with malignant cells in regional lymph nodes no greater than 0.2 millimeter (mm) and no more than 200 cells; bladder prolapse congenital, colon polyps, continuous positive airway pressure dependence (CPAP), degenerative disc disease (DDD), gastroesophageal reflux disease (GERD), hiatal hernia, hypertension, hyperlipidemia, interstitial cystitis, menopause (at age 50 years old), mitral regurgitation, morbid obesity with body mass index (BMI) of 50.0-59.9 adult HCC (sic), obstructive sleep apnea (OSA) and on CPAP, osteoarthritis, sleep apnea, vitamin D deficiency, epistaxis, and depression. The patient experienced nausea and vomiting when treated with Demerol (pethidine hydrochloride).  The patient received covid-19 vaccine ad26.cov2.s (suspension for injection, intramuscular, batch number: 1802068, and expiry: unknown) dose was not reported, dose number in series was 1, 1 total, administered on 30-MAR-2021 for an unspecified indication. Concomitant medications included ascorbic acid/iron (iron plus C) for low serum iron; unspecified medications for delirium; Aspirin (acetylsalicylic acid), Arimidex (anastrozole), Vitamin D (colecalciferol), Cymbalta (duloxetine hydrochloride), Neurontin (gabapentin), and Mucinex (guaifenesin), all drugs for unknown indications.  On 09-NOV-2021, following vaccination with covid-19 vaccine ad26.cov2.s, the patient experienced haematuria, incontinence, tremor, urinary tract infection and was seen by a primary care physician (PCP) who prescribed cephalexin as treatment. On 29-NOV-2021, the patient fell while shopping, hit her head in the parking lot, had a head injury, following which the Emergency Medical Services (EMS) was called and the patient was assessed. On 30-NOV-2021, the patient was seen at the emergency department (ED). On the same date, the patient experienced shortness of breath (dysnpnea), confusion, cough, worsening headache, asthenia (weak), was tested positive for severe acute respiratory syndrome coronavirus 2 polymerase chain reaction (SARS-CoV-2 PCR) test (covid-19 and confirmed clinical vaccination failure) and presented to the ED with these complaints. A computerized tomogram (CT) brain without acute pathology and without inferior vena cava (IVC) was done which was abnormal (positive for new hypodensity in the left thalamus with suspicion for infarction of unclear chronicity); another CT showed the patient had covid-19 infection and was discharged home. The patient had worsening lethargy, poor oral intake (hypophagia), delirium, and weakness over the past several days and workup in the ED was concerning for left thalamic infarction. On 30-NOV-2021, the patient also experienced syncope, embolic stroke, ischaemic stroke, depressed level of consciousness, encephalopathy, thalamic infarction, unresponsive to stimuli, agitation, hypersomnia (sleeping about 14-16 hours a day), patient was restraint, had somnolence, fatigue, gastrointestinal tube insertion, blood folate was normal, blood thyroid stimulating hormone (TSH) decreased to 1.84 (NR: not provided), vitamin b12 was normal, glycosylated haemoglobin was normal at 5.5 (NR: not provided), urine analysis normal (negative for UTI), urine drug screen (UDS) was negative, magnetic resonance imaging head (result not reported), chest x-ray was abnormal and showed covid-19 pneumonia (dose number in series was 1). The patient visited the emergency room (ER) for all reported events. The patient had an episode of confusion on a 03-DEC-2021 (Friday) when she was trying to sort out her medications for the next week and she has taken care of her own medications for years but was having a lot of difficulty on Friday. On 05-DEC-2021, the patient was again tested positive for covid-19. On 06-DEC-2021, the patient was hospitalized with chief complaint of pneumonia due to covid-19. She was examined at bedside and was groggy but arousable. She denied any pain, shortness of breath, headache when asked but then falls asleep and does not answer any questions. A plan was made to continue stroke power plan. The patient was unable to take per oral intake (improvement awaited in her mentation). The patient was agitated and received Benadryl (diphenhydramine) and then Haldol (haloperidol). In regard to covid pneumonia, she did not require supplemental oxygen but was required to complete 10 days of Decadron (dexamethasone). The etiology for acute encephalopathy was unclear as patient was unable to consistently follow commands to rule out focal deficits, possible stroke vs hypertensive urgency, emergency vs infection, delirium. Continuous pulse oximetry was warranted for the patient. Psychiatry was consulted for agitation and confusion. The patient remained confused and had bilateral wrist restraint. On 09-DEC-2021, neuropsychiatry assessed the patient to have capacity to assign durable power of attorney (DPOA) but not to determine a discharge plan. Unfortunately, this DPOA document had not been completed. On 13-DEC-2021, upon doctor's assessment, the patient was unable to name a medical DPOA hence, guardianship would be pursued as discussed with social worker. A court-appointed guardianship was awaited as patient was no longer able to assign DPOA at the time of reporting. On 13-DEC-2021, the patient was continuing unspecified medications for delirium (recommendations ongoing). Upon interview on 14-DEC-2021, the patient was still had waxing and waning levels of alertness but was able to respond to more questions. She denied any current physical complaints, reported that she has been sleeping well, felt tired in the morning and acknowledged feeling confused. The patient slept well overnight but continued to wax and wane. Acute encephalopathy was ongoing likely due to acute delirium, embolic ischemic stroke (CT brain was concerning for left thalamic stroke and MRI brain findings were noted). The patient's anti-coagulant therapy with Xarelto was replaced with Lovenox (enoxaparin sodium) while patient was refusing to take orally; acetylsalicylic acid (ASA) and Crestor (rosuvastatin calcium) was for home. Since patient was experiencing delirium or is at a high risk of delirium, it was advised to keep the blinds open and lights on during daylight hours; to frequently re-orient to situation, location, city, state, time, time of day, date, month, season; to make every effort to obtain assistive devices such as glasses, hearing aids, dentures and other medical prostheses; to minimize daily naps to less than three per day and less than 60 minutes if possible; to keep room lights at full brightness If patient is experiencing delirium during naps to maximize daytime suppression of physiological melatonin production and minimize circadian rhythm disruption; to consider requesting scheduled melatonin if patient has it ordered PRN (when necessary); to minimize extraneous noise and interruptions as well as artificial ambient lighting during night time hours; and to minimize unnecessary vital checks and lab draws attempting to obtain these while patient is awake if at all possible. At the time of reporting, the patient was awake, interacted with her son appropriately, was still eating and drinking and has been falling more (as per patient's son). The patient's headaches improved and she denied having headache, but still has cough (not continuous) at the time of report. The patient was hospitalized for 9 days. The action taken with covid-19 vaccine ad26.cov2.s was not applicable. The patient recovered from headache, had not recovered from agitation, anticoagulant therapy, asthenia, blood folate normal, blood thyroid stimulating hormone decreased, covid-19, covid-19 pneumonia, chest x-ray abnormal, computerised tomogram, computerised tomogram head abnormal, confusional state, cough, delirium, depressed level of consciousness, drug screen negative, dyspnoea, embolic stroke, encephalopathy, fall, fatigue, gastrointestinal tube insertion, glycosylated haemoglobin normal, haematuria, head injury, hypersomnia, hypophagia, incontinence, ischaemic stroke, lethargy, magnetic resonance imaging head, patient restraint, sars-cov-2 test positive, somnolence, syncope, thalamic infarction, tremor, unresponsive to stimuli, urinary tract infection, urine analysis normal, and vitamin b12 normal, and the outcome of confirmed clinical vaccination failure was not reported. This report was serious (Hospitalization Caused / Prolonged, and Other Medically Important Condition). This report was associated with product quality complaint: 90000208917. The suspected product quality complaint has been confirmed to be the reported allegation could not be confirmed. A manufacturing related root cause could not be identified, based on the PQC evaluation/investigation performed.  Additional information was received from Central Complaint Vigilance Department (CCVUSA) on 07-JAN-2022. The following information was updated and incorporated into case narrative: Product Quality Complaint (PQC) investigation results.; Sender's Comments: V1: Follow up information updates about PQC investigation result. No change in prior causality assessment. 20211255660 -Covid-19 vaccine ad26.cov2.s -Confirmed clinical  vaccination failure . 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: SPECIAL SITUATIONS. 20211255660-Covid-19 vaccine ad26.cov2.s-Ischaemic stroke. 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 20211255660-Covid-19 vaccine ad26.cov2.s-agitation, anticoagulant therapy, blood folate normal, blood thyroid stimulating hormone decreased, covid-19, covid-19 pneumonia, chest x-ray abnormal, computerised tomogram, computerised tomogram head abnormal, confusional state, cough, delirium, depressed level of consciousness, drug screen negative, dyspnoea, embolic stroke, encephalopathy, fall, gastrointestinal tube insertion, glycosylated haemoglobin normal, haematuria, head injury, hypersomnia, hypophagia, incontinence, lethargy, magnetic resonance imaging head, patient restraint, sars-cov-2 test positive, somnolence, syncope, thalamic infarction, tremor, unresponsive to stimuli, urinary tract infection, urine analysis normal, vitamin b12 normal, Headache.. 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). 20211255660-Covid-19 vaccine ad26.cov2.s-Asthenia, Fatigue. This event(s) is labeled per RSI and is therefore considered potentially related.