STROKE AFTER RECEIVING JANSSEN COVID-19 VACCINE BOOSTER DOSE; This spontaneous report received from a patient concerned a 43 year old female. Initial information processed with additional information received from reporter on 15-DEC-2021. The patient's height was 177.8 cm, and weight were not reported. The patient's concurrent conditions included: environmental allergy, non alcoholic, birth control, and non smoker, and other pre-existing medical conditions included: The patient had no known medical condition and no known drug allergies. The patient did not have any drug abuse/illicit drug use. The patient did not have any other medical history or relevant pre-existing condition. Patient had no illness at time of vaccination. Patient had no history of similar event. Patient had no history of any allergy to vaccine, drug, or food. Patient had no pre-existing acute illness 30 days prior to vaccination. Patient had no history of hospitalization in last 30days, with cause. Patient had no family history of any disease (relevant to vaccination) or allergy. The patient was not not pregnant or breastfeeding at the time of reporting. The patient did not have COVID-19 infection. The patient experienced flu like symptoms, fever, chills, achiness (Dose number in series 1) when received covid-19 vaccine ad26. cov2. s (suspension for injection, route of admin not reported, batch number: 205A21A, expiry: unknown) dose was not reported, 1 total, administered on 12-APR-2021 for prophylactic vaccination (Dose number in series 1). The patient received covid-19 vaccine ad26.cov2.s (suspension for injection, intramuscular, batch number: 211A21A, expiry: 14-DEC-2021, (Gauge/length of the needle: 23 g, 0.6 mm*25 mm, Temperature 38-41 F)) 0.5 ml, 1 total, administered on 08-Dec-2021;12:00 to right arm for prophylactic vaccination (Dose number in series 2). No issue related to the storage of the vaccine. Concomitant medications included montelukast sodium for allergies, levocetirizine dihydrochloride for allergies, and drospirenone/ethinylestradiol betadex clathrate for birth control.  On 08-DEC-2021, immediately after she received the booster dose, she felt a tingling sensation in her mouth and that her mouth went numb. At that time the nurse practitioner given diphenhydramine hydrochloride (benadryl) and lansoprazole (prevacid) and that afterwards nothing happened. The patient passed the phone to other person to complete her report stating previously that she just had a stroke (Dose number in series 2) and so may not be able to complete the call. Reporter stated that, On 09-DEC-2021, around 09:00 to 10:00 A.M, at work the patient started to feel that her vision went blank, her arm started to tingle, she could not make words and so she went to the health facility. At the hospital, she was given the standard of care including an Chest X-ray, Computerised tomogram head and neck, Echocardiogram, MRI brain (Magnetic resonance imaging) and blood work and then was administered Tissue plasminogen activator (TPA) alteplase. Patient visited the emergency room. Patient was stayed in the hospital for a total of about 24 hours was discharged on 10-DEC-2021 with prescriptions for clopidogrel and lipitor. The action taken with covid-19 vaccine ad26.cov2.s was not applicable. The patient was recovering from tingling sensation in her mouth/arm started to tingle/face tingled, and stroke after receiving Janssen covid-19 vaccine booster dose This report was serious (Hospitalization Caused / Prolonged). This case, involving the same patient is linked to 20211228737.; Sender's Comments: V0:20211229198-COVID-19 VACCINE AD26.COV2.S-Stroke after receiving Janssen covid-19 vaccine booster dose. 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).