CEREBRAL ARTERY OCCLUSION; ENCEPHALOPATHY; CEREBRAL SMALL VESSEL ISCHAEMIC DISEASE; HYPOXIA; ENCEPHALOPATHY; METABOLIC ENCEPHALOPATHY; HYPOXIA; SEPSIS; LACUNAR INFARCTION; COVID-19; METABOLIC ENCEPHALOPATHY; STENOSIS; PNEUMONIA; DYSPHAGIA; SEPSIS; ANGIOGRAM PULMONARY ABNORMAL; COVID-19; CEREBRAL SMALL VESSEL ISCHAEMIC DISEASE; STENOSIS; STAPHYLOCOCCUS TEST NEGATIVE; DYSPHAGIA; LACUNAR INFARCTION; FALL; PNEUMONIA; ANGIOGRAM PULMONARY ABNORMAL; CEREBRAL ARTERY OCCLUSION; SARS-COV-2 TEST POSITIVE; FALL; STAPHYLOCOCCUS TEST NEGATIVE; SARS-COV-2 TEST POSITIVE; This spontaneous report received from a health care professional by a Regulatory Authority VAERS (Vaccine Adverse Event Reporting System) concerned an 85 year old female of an unspecified race and ethnicity. The patient's height, and weight were not reported. The patient's past medical history included: supraventricular tachycardia, chronic diastolic congestive heart failure (history of heart failure with preserved ejection fraction), left displaced femoral neck fracture, sp fixation (spinous process), multiple CVA (Cerebrovascular accident), tobacco abuse, recurrent UTI's (Urinary tract infection), uncontrolled hypertension, and covid-19, and concurrent conditions included: cerebrovascular small vessel disease, essential primary hypertension, bilateral carotid artery stenosis, mild aortic stenosis, peripheral vascular disease unspecified, digestive ileus, rectal prolapse, recurrent clostridium difficile diarrhea, small bowel obstruction, dysphagia (oropharyngeal phase), gastro-esophageal reflux disease (without esophagitis), endocrine hypothyroidism unspecified, psychological severe vascular dementia (without behavioral disturbance, psychotic disturbance, mood disturbance or anxiety unspecified, dementia unspecified, severity without behavioral disturbance psychotic disturbance, mood disturbance and anxiety), respiratory interstitial lung disease, pneumonia unspecified organism, urinary chronic kidney disease stage 3 unspecified, urinary retention, acute kidney injury, dyslipidemia, unintentional weight loss, cigarette nicotine dependence in remission, anemia unspecified, epigastric hernia, vitamin d deficiency, dizziness, constipation, debility, protein-calorie malnutrition, hyponatremia (Frail elderly), muscle weakness generalized, polyosteoarthritis unspecified, cardiac pacemaker, restless legs syndrome, and allergies to statins (HMG-CoA Reductase Inhibitors (Muscle Symptoms)), and other pre-existing medical conditions included: The patient need assistance with personal care. The patient received covid-19 vaccine ad26.cov2.s (suspension for injection, route of admin not reported, batch number: 213D21A and expiry: Unknown) dose was not reported, 1 total, dose 1 was administered on 23-JAN-2022 for an unspecified indication. Age at time of vaccination 85 years old. No concomitant medications were reported. On 14-DEC-2022, the patient presented with acute encephalopathy and a fall. Encephalopathy was likely multifactorial secondary to COVID (covid-19), hypoxia and baseline dementia (likely at baseline not even able to know her own birthday, dependent for ADLs (activities of daily living)), also experienced metabolic encephalopathy secondary to COVID, hypoxia, sepsis, cerebral artery occlusion, cerebral small vessel ischaemic disease, lacunar infarction, pneumonia (possible aspiration versus superimposed community-acquired), stenosis, dysphagia (failing swallow secondary to dysphagia) and was hospitalized (date unspecified) with covid complications and positive PCR (Polymerase chain reaction). Laboratory data included: Angiogram pulmonary abnormal, SARS-CoV-2 test Positive, Staphylococcus test Negative and PCR Positive (Covid Detected). Laboratory data (dates unspecified) included: Brain CT (Computerised tomogram) no acute process, Computerised tomography (CTA) right internal bulb 70% stenosis multifocal intracranial stenosis P2 segment occlusion on right, MRI (Magnetic resonance imaging) shown old lacunars chronic small vessel ischemia, Methicillin-resistant staphylococcal aureus test Negative. It was reported that the patient was continued with ASA ( acetylsalicylic acid) and as per Neuro recommendations. COVID-19 with hypoxia-resolved at the time of reporting patient was weaned to room air. The patient was hospitalized for 10 days. Treatment medications (dates unspecified) included: vancomycin (vancomycin discontinued as Methicillin-resistant staphylococcal aureus test was negative), acetylsalicylic acid, cefepime for 5 days, remdesivir for 5 days, and dexamethasone for 10 days. The action taken with covid-19 vaccine ad26.cov2.s was not applicable. The patient recovered from cerebral artery occlusion, cerebral small vessel ischaemic disease, encephalopathy, hypoxia, lacunar infarction, metabolic encephalopathy, pneumonia, sepsis, covid-19, stenosis, dysphagia, fall, angiogram pulmonary abnormal, sars-cov-2 test positive, and staphylococcus test negative. This report was serious (Hospitalization Caused / Prolonged). This report was associated with a product quality complaint 90000270394. The suspected product quality complaint has been confirmed to be the reported allegation could not be determined. A manufacturing related root cause could not be identified based on the PQC evaluation/investigation performed.  Additional information received from Central Complaint department on 16-FEB-2023. The following information was updated and incorporated into the case narrative: Product quality complaint investigation result.; Sender's Comments: V1: This follow up adds information about  Product quality complaint investigation result. This does not alter previous causality assessment of the reported events.   20230212621-cerebral artery occlusion, cerebral small vessel ischaemic disease, lacunar infarction, encephalopathy, metabolic encephalopathy, pneumonia, sepsis, stenosis, dysphagia. The event 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. Specifically: MEDICAL HISTORY. Therefore, this event is considered inconsistent with vaccine administration.  20230212621-angiogram pulmonary abnormal, fall, staphylococcus test negative. The event 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. Therefore, the WHO Causality is considered indeterminate. The company causality is considered unassessable.  20230212621-hypoxia, covid-19, sars-cov-2 test positive. The event is deemed to be scientifically implausible, i.e., there is scientific evidence against a drug/event relationship; AND there is no known class effect. Therefore, this event is considered inconsistent with vaccine administration.