SHORTNESS OF BREATH AFTER WALKING; SWELLING IN BACK OF LEFT LEG BEHIND KNEE LEFT SIDE THAT WAS PAINFUL; HEADACHES; BURNING SENSATION IN VEINS IN LEGS WHICH MAKES ITCH AND BURNS ON THE INSIDE OF BODY; TINGLING IN TORSO AND LEGS; TINNITUS; JOINTS FELT ACHY; CALF PAIN, WALKING FELT LIKE CALF GOING TO EXPLODE AND HURTS TO WALK; BURNING IN RADIUS AND ULNA OF ARMS FROM ELBOW TO HAND; TACHYCARDIA; ANXIETY; This spontaneous report received from a patient concerned a 47 year old female. The patient's height, and weight were not reported. The patient's past medical history included cervical neck fusion which maybe healing from surgery could have contributed. The patient received covid-19 vaccine ad26.cov2.s (suspension for injection, route of admin not reported, batch number: 204A21A expiry: 05-NOV-2021) 1 total, administered on 09-SEP-2021 to left deltoid for prophylactic vaccination. No concomitant medications were reported.  On 10-SEP-2021, day after receiving the vaccine, the patient had tachycardia and anxiety that went away after about 2 weeks. Tachycardia would last a few minutes and go back to normal. The patient would get a little pressure and electrical zaps still sometimes but not often now, heart stuff got better but not as much like little shocks. On 18-SEP-2021, the patient went to emergency room and spent night for swelling in back of left leg, behind knee, just left side. It was painful, but no blood clot (checked at hospital). On 27-SEP-2021, the patient visited emergency room overnight for shortness of breath after walking, 30 minutes in could not breath. On an unspecified date in OCT-2021, the patient felt burning in radius and ulna of arms from elbow to hand, had been happening for about 4 to 5 days. On 18-OCT-2021, the patient's joints felt achy like an old person. The patient had tinnitus, lots of calf pain, walking felt like calf going to explode. Leg pain in calf for about a month, would come and go, sometimes hurts to walk and sometimes it was not so bad. The patient had tingling in torso and legs and seems better lately. On 23-OCT-2021, the patient started having a burning sensation in veins (like thick poison) in legs. It will make the patient itch and burns on the inside of body. On an unspecified date, the patient experienced headaches. The patient was hospitalized for unspecified days. The action taken with covid-19 vaccine ad26.cov2.s was not applicable. The patient recovered from tachycardia, and anxiety on 23-SEP-2021, was recovering from tingling in torso and legs, had not recovered from tinnitus, calf pain, walking felt like calf going to explode and hurts to walk, swelling in back of left leg behind knee left side that was painful, joints felt achy, and burning sensation in veins in legs which makes itch and burns on the inside of body, and the outcome of shortness of breath after walking, headaches and burning in radius and ulna of arms from elbow to hand was not reported. This report was serious (Hospitalization Caused / Prolonged).; Sender's Comments: V0: 20211049645-COVID-19 VACCINE AD26.COV2.S-swelling in back of left leg behind knee left side, shortness of breath after walking. 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).