SEVERE BLOOD CLOT IN RIGHT FOOT; RED MARK BEHIND THE LEFT CALVE THAT MOVING UP; TERRIBLE PAIN; LOST SO MUCH WEIGHT; LEFT FOOT DOES NOT RESPOND ON TOUCH; PATIENT CANNOT MOVE; CANNOT EAT; NOT RESPONDING; DOES NOT COMMUNICATE; PATIENT SLUMPED, COULD NOT HOLD HEAD, COULD NOT SIT AND LOOKED VERY BAD; FOOT INJURY; WAS NOT BREATHING WELL, BREATHING THROUGH THE MOUTH; This spontaneous report received from a consumer concerned a 91 year old female of unspecified race and ethnicity. The patient's height, and weight were not reported. The patient's past medical history included: injury, and concurrent conditions included: dementia, and other pre-existing medical conditions included: the patient took Vitamins and Minerals. The patient received covid-19 vaccine ad26.cov2.s (suspension for injection, route of administration not reported, batch number: 041A21A, and expiry: 19-SEP-2021) dose was not reported, one total administered on right arm on 05-APR-2021 for prophylactic vaccination. Concomitant medications included amlodipine, and sertraline hydrochloride.  On APR-2021, after the vaccine for 3 or 4 days straight the patient was not breathing very well, and was breathing through mouth. On AUG-2021, the patient experienced cold dark right foot and doctor instructed the patient to warm up the leg, the patient experienced low pulse in the right leg, right foot did not look right, it was dark and swollen and the patient had never seen that before, black marks at the bottom of the toes, the patient took for examination at the hospital, and the patient had an injury to the foot (even though found no evidence of an injury). The physician told patient that the patient needed an X-Ray, made an ultrasound exam and found that patient had a low pulse in the leg. On 15-AUG-2021, the patient experienced patient slumped, could not hold head, could not sit and looked very bad. The patient was hospitalized on 08-SEP-2021 and experienced blood clot in foot, had an issue with a blood clot that causes the foot to be like that, tried to put a stent in patient's leg but it could not be done (patient had one blood vessel at the back of her knee instead of two) so they recommended amputation above the knee, family declined amputation and brought patient home on 13-SEP-2021 home. Monitored the feet, eventually the whole right foot became black. On an unspecified date the patient experienced no feelings in the right feet, left feet does not respond on touch, cannot move, red mark behind the left calve that moving up, cannot eat, does not communicate, terrible pain, lost so much weight because was not eating.  The patient was not taking much but for pain management, caregiver dilutes ibuprofen.  The action taken with covid-19 vaccine ad26.cov2.s was not applicable. The patient recovered from was not breathing well, breathing through the mouth, had not recovered from red mark behind the left calve that moving up, and the outcome of foot injury, patient slumped, could not hold head, could not sit and looked very bad, does not communicate, terrible pain, lost so much weight, left foot does not respond on touch, severe blood clot in right foot, patient cannot move, cannot eat and not responding was not reported. This report was serious (Hospitalization Caused / Prolonged).; Sender's Comments: V0 20211002682-COVID-19 VACCINE AD26.COV2.S-severe blood clot in right foot. 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).