CEREBROVASCULAR ACCIDENT; ENCEPHALOPATHY; HYPOKALAEMIA; MYOCARDIAL INFARCTION; RENAL IMPAIRMENT; METABOLIC ENCEPHALOPATHY; AGITATION; ANTIPLATELET THERAPY; ANXIETY; BLOOD CREATININE INCREASED; BLOOD PRESSURE SYSTOLIC INCREASED; COVID-19; COMPUTERISED TOMOGRAM HEAD ABNORMAL; DYSPHAGIA; FULL BLOOD COUNT ABNORMAL; HYPERTENSION; INTENSIVE CARE; LEUKOCYTOSIS; MAGNETIC RESONANCE IMAGING ABNORMAL; MENTAL STATUS CHANGES; NERVOUS SYSTEM DISORDER; OEDEMA; SARS-COV-2 TEST POSITIVE; TREATMENT NONCOMPLIANCE; This spontaneous report received from a health care professional by a Regulatory Authority VAERS (Vaccine Adverse Event Reporting System, VAERS ID 2577987) concerned a 62 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: cerebrovascular accident (Cerebrovascular accident CVA due to embolism of carotid artery), integumentary tinea capitis, and alopecia, and concurrent conditions included: cardiovascular hypertension (HTN) benign, tobacco use, acute encephalopathy, and hypertensive encephalopathy (poorly controlled hypertension and medical noncompliance). The other pre-existing medical conditions included: The patient had no know allergies. The patient previously received covid-19 vaccine ad26.cov2.s (unspecified manufacturer) (Dose number in series 1) (suspension for injection, route of admin not reported, batch number:1855194, expiry: UNKNOWN) dose was not reported, 1 total, administered on an unspecified date for an unspecified indication.  It was unknown whether the patient experienced any adverse events following vaccination with covid-19 vaccine ad26.cov2.s (unspecified manufacturer) (Dose number in series 1).  The patient received covid-19 vaccine ad26.cov2.s (Dose number in series 2) (suspension for injection, route of admin not reported, batch number: 042A21A expiry: UNKNOWN) dose was not reported, 1 total, administered on 12-NOV-2022 for an unspecified indication. Age at time of vaccination 62 years old. Concomitant medications included aspirin low dose (acetylsalicylic acid), norvasc (amlodipine besilate), lipitor (atorvastatin calcium), and catapres TTS (clonidine) for drug used for unknown indication.  On 20-DEC-2022, the patient presented with chief complaint of altered mental status (mental status changes) (Dose number in series 2). On presentation, the patient was noted to be hypertensive systolics (hypertension) (blood pressure systolic increased) in the 240s creatinine (blood creatinine increased), 28 hypokalemic (hypokalaemia), complete blood count notable for leukocytosis (leukocytosis) (full blood count abnormal) (Dose number in series 2). A computerized tomography (CT) was performed and showed nonspecific low attenuation in both cerebral hemispheres (computerised tomogram head abnormal) (Dose number in series 2). The patient was admitted for workup of strokes and altered mental status. The patient initially admitted to the intensive care unit (intensive care) required IV blood pressure medications and transferred to progressive care unit once titrated off of intravenous (IV) medications (Dose number in series 2). The patient continued to be non-compliant (treatment noncompliance) with oral medications throughout her stay requiring IV supplementation to her blood pressure regimen (Dose number in series 2). The patient was tested positive for COVID-19 family (sars-cov-2 PCR test positive), declined remdesivir and she was not requiring oxygen (Dose number in series 2). Initial repeat CT was concerning for acute CVA (cerebrovascular accident) right caudate head lacunar infarct, question microhemorrhage (Dose number in series 2). The initial magnetic resonance imaging (MRI) was a poor study secondary to patient agitation (magnetic resonance imaging abnormal) (Dose number in series 2). The repeat studies were obtained with IV medications for anxiety/sedation. The MRI showed small attenuated acute infarcts right caudate nucleus right lateral ventricle, left temporal lobe (nervous system disorder) (Dose number in series 2). The patient was started on dual anti-platelets (antiplatelet therapy) and seen by neurology (Dose number in series 2). The MRI was obtained without large vessel occlusion or stenosis. The patient required prolonged stay secondary to encephalopathy edema (oedema) secondary to new CVAs, COVID and metabolic encephalopathy (Dose number in series 2). The patient had renal impairment (Dose number in series 2). The renal function was improved following IV fluids. The blood pressure regimen was titrated up former she no longer required IV medications. She was saw by physical therapy (PT) and occupational therapy (OT ) with recommendations for rehab. The family declined wanting to take patient home. The patient will be discharged on 21 day therapy dual anti-platelets followed by aspirin monotherapy. Discharge was delayed secondary to holiday difficulty with coordination of home care. The family chose to pursue home care from primary outpatient. The patient had dysphagia which improved prior to discharge was able to eat normal diet. The patient experienced myocardial infarction (Dose number in series 2). The number of days of hospitalization was 13 days. The latency was 38 days. The action taken with covid-19 vaccine ad26.cov2.s was not applicable. The patient recovered from agitation, antiplatelet therapy, anxiety, blood creatinine increased, blood pressure systolic increased, covid-19, cerebrovascular accident, computerised tomogram head abnormal, dysphagia, encephalopathy, full blood count abnormal, hypertension, hypokalaemia, intensive care, leukocytosis, magnetic resonance imaging abnormal, mental status changes, metabolic encephalopathy, myocardial infarction, nervous system disorder, oedema, renal impairment, sars-cov-2 test positive, and treatment noncompliance. This report was serious (Hospitalization Caused / Prolonged). This report was associated with product quality complaint. 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 was received from Complaint department on 06-MAR-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.  20230244617-full blood count abnormal, leukocytosis , intensive care, anxiety, nervous system disorder. 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.   20230244617-cerebrovascular accident, antiplatelet therapy, encephalopathy, agitation, dysphagia, myocardial infarction, metabolic encephalopathy, blood pressure systolic increased, hypertension, mental status changes, magnetic resonance imaging abnormal, computerised tomogram head abnormal, renal impairment, blood creatinine increased, hypokalaemia, oedema. 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.   20230244617-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.   20230244617-treatment noncompliance. The case causality is considered INCONSISTENT. Rationale: Event treatment noncompliance described in context of oral medications for blood pressure  and not with vaccine.