CAT SCAN HEAD - SOMETHING IN HEAD; FEELING LIKE A BLOOD CLOT ON INNER UPPER THIGH OF RIGHT LEG; DIFFICULTY BREATHING; CALCIFICATION OF LUNGS; NUMBNESS IN BOTH FEET AND TOES; DIZZINESS; OFF BALANCE; RIGHT LEG TINGLING/FEELS LIKE WATER RUSHING; FELT LIKE BUGS RUNNING IN HEAD; ELECTRICAL SHOCK LIKE BUGS IN HAIR; SQUEEZING IN FACE; WHOLE BLOOD WAS DROPPING OUT OF BODY; This spontaneous report received from a patient concerned an 84 year old female. The patient's weight was 230 pounds, and height was 66 inches. The patient's past medical history included stroke, and concurrent conditions included atrial fibrillation, allergy to medications, non-smoker, and non-alcohol user. The patient was not pregnant at the time of reporting and the patient had no drug abuse or illicit drug use. The patient received covid-19 vaccine ad26.cov2.s (suspension for injection, route of admin not reported, batch number: 041A21A, and expiry: 05-AUG-2021) dose was not reported, 1 total, administered on 04-APR-2021 to right arm for prophylactic vaccination. Concomitant medications included diltiazem hydrochloride for atrial fibrillation, and warfarin sodium for stroke. On 01-MAR-2021, the patient's laboratory data included Doppler scan and results were normal. On 04-APR-2021, the patient got dizzy right after the vaccination and off balance which exasperated everything. On the same day, the patient experienced tingling in right leg, felt like water rushing, both feet toes were numb, on right side felt like a blood clot on inner right thigh, difficulty breathing, calcification of lungs, felt like bugs running in her head, electrical shock, like bugs in her hair and squeezing in her face. The patient felt like her whole blood was dropping out of her body. The patient described everything comes and goes and one day it was there and another day it was not, then it came back. It was reported that, the patient visited her physician for the tenderness in her leg for possible blood clot issue and she did not know the results. On 29-JUN-2021, the patient's laboratory data included computerised tomogram (CAT scan) of brain and lungs which was abnormal, showed calcification on the lungs and that something was in her head. The patient had visited an ear, nose, throat (ENT) physician, internist, pulmonary physician, and cardiologist and it was made aware that all the side effects were from the vaccination. The patient had scheduled upcoming appointment with gastroenterologist physician. The action taken with covid-19 vaccine ad26.cov2.s was not applicable. The patient recovered from dizziness on 04-APR-2021, had not recovered from right leg tingling/feels like water rushing, numbness in both feet and toes, feeling like a blood clot on inner upper thigh of right leg, difficulty breathing, calcification of lungs, felt like bugs running in head, squeezing in face, electrical shock like bugs in hair, and whole blood was dropping out of body, and the outcome of off balance and CAT scan head - something in head was not reported. This report was serious (Other Medically Important Condition).; Sender's Comments: V0 20210728298-covid-19 vaccine ad26.cov2.s -this case concerns a 84 year old female-feeling like a blood clot on inner upper thigh of right leg. 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).