CEREBRAL ARTERY OCCLUSION; CEREBROVASCULAR ACCIDENT; ATRIAL SEPTAL DEFECT; THROMBECTOMY; CONFIRMED COVID-19 INFECTION; SARS-COV-2 TEST POSITIVE; CHILLS; FATIGUE; HEADACHE; CONFIRMED CLINICAL VACCINATION FAILURE; This spontaneous report received from a health care professional via a Regulatory Authority Vaccine Adverse Event Reporting System (VAERS ID: 1463769), concerned a 35 year old female patient of unspecified race and ethnic origin. The patient's height, and weight were not reported. The patient's concurrent condition included antiphospholipid syndrome. The patient had no allergies reported. On 14-JAN-2021, the patient was tested positive for coronavirus disease (COVID-19) via the COVID-19 polymerase chain reaction (PCR) test. The patient received covid-19 vaccine ad26.cov2.s (suspension for injection, route of administration was not reported, batch number: 201A21A and expiry: unknown) dose was not reported, 1 total, administered on 08-APR-2021 for prophylactic vaccination. Concomitant medication included Xarelto (rivaroxaban). On 05-JUN-2021, the patient experienced onset of chills, fatigue, headache and was tested positive for COVID-19 via COVID-19 PCR test [severe acute respiratory syndrome coronavirus 2 (SARS-COV-2) test positive, confirmed covid-19 infection and confirmed clinical vaccination failure]. The patient went to emergency room visit and was hospitalized (date unspecified in report). On 05-JUN-2021, she had acute right middle cerebral artery (R MCA) ischemic stroke (cerebrovascular accident), 2/2 M1 occlusion (cerebral artery occlusion) status post (S/P) thrombectomy '(HCC)' (as reported), and had atrial septal defect [patent foramen ovale (PFO)]. On 12-JUN-2021, she was discharged to inpatient rehabilitation. The patient was hospitalized for 8 days. The action taken with covid-19 vaccine ad26.cov2.s was not applicable. The outcome of the atrial septal defect, cerebral artery occlusion, cerebrovascular accident, chills, confirmed covid-19 infection, fatigue, headache, thrombectomy, SARS-COV-2 test positive and confirmed clinical vaccination failure was not reported. This report was serious (Hospitalization Caused / Prolonged, Other Medically Important Condition, Life Threatening, and Disability Or Permanent Damage). This report was associated with product quality complaint : 90000187446.  Version created to amend previously reported information on 23-JUL-2021. Upon review following information amended. Event chills, fatigue and headache were updated from labeled to unlabeled. Additional information received from Consumer Complaint Vigilance Organization on 27-JUL-2021. The following information updated and incorporated into the case narrative. product quality complaint number was added.; Sender's Comments: V1:  Follow-up information updates the labeling and adds a product quality complaint number; this does not change the previous assessment.  This spontaneous report received from a Regulatory Authority [VAERS ID: 1463769] concerns a 35-year-old female patient of unspecified ethnicity who had an acute right middle cerebral artery (R MCA) ischemic stroke with cerebral artery occlusion and was hospitalized 58 days after receiving the Janssen Covid-19 vaccine. Concurrent condition included antiphospholipid syndrome. The patient was previously COVID-19 polymerase chain reaction (PCR) test positive 3 month prior to vaccination.  On the day of hospitalization, the patient noted chills, fatigue, headache; COVID-19 PCR test was positive.  The patient underwent thrombectomy "HCC"; atrial septal defect was noted.  The subject's anti-phospholipid syndrome and SARS-COV-2 infection may have increased the risk for the events to occur. However, considering the temporal relationship with vaccination, a relationship with Janssen Covid-19 vaccine cannot be ruled out. Therefore, the relationship is considered indeterminate.