CHRONIC CHEST TIGHTNESS; LABORED BREATHING UPON MOVEMENT; WITH MOVEMENT OXYGEN LEVEL WENT DOWN TO 70 TO 80 PERCENTAGE; SWEATS; CHILLS; SORE ARM FOR 1 WEEK; BURNED INTENSELY AT THE TIME OF INJECTION; HEADACHE; MUSCLE ACHES ALL OVER THE BODY; LOW GRADE FEVER; This spontaneous report received from a patient concerned a 47 year old female. The patient's weight was 155 pounds, and height was 67 inches. The patient's past medical history included chest infection and ended up with bronchitis in her late 30s. When the patient was a teenager and was active in sports sometimes would get short of breath. The patient's concurrent conditions included non smoker, and abstains from alcohol, and other pre-existing medical conditions included no known prior history and did not have any drug abuse/illicit drug use. The patient was previously treated with salbutamol for bronchitis and with nebulizer for short of breath. The patient experienced hives all over body when treated with amoxicillin. The patient received covid-19 vaccine ad26.cov2.s (suspension for injection, route of admin not reported, and batch number: 201A21A expiry: 21-SEP-2021) dose was not reported, 1 total, administered on 09-AUG-2021 at around 15:30 to left arm for prophylactic vaccination. No concomitant medications were reported.  On 09-AUG-2021, the patient experienced intense burning at the time of injection and had sore arms for one week. Half an hour later the patient had a headache and 2 hours later had muscle aches all over her body, low grade fever, chills and sweating which all were resolved in morning after 48 hours. The next morning on 10-AUG-2021 the patient felt tight chest, something that had not gone away and she had chronic chest tightness and labored breathing. The patient visited ER (emergency room) twice. On 14-AUG-2021, the patient visited ER for second time and got admitted. The patient underwent lab tests such as blood clots (negative for pulmonary embolism), troponin, D-Dimer, COVID (rapid tests), 5 times EKGs (electrocardiogram), 2 times CT (computerised tomogram) scans, 2 times chest X-Rays, Stress test with lexiscan (because the patient could not perform on treadmill) and they all were negative. They ruled out myocarditis or pericarditis and did ultrasound for the possibility of fluid around the lung which was negative. They found mitral valve thickening which were told it was not significant. They also pointed out to anxiety but the reporter said that she knew that was not anxiety. The patient's main concern was that she had labored breathing with any movement or positioning and she had chronic chest tightness that she said she had been in intermittent ambulatory distress. The patient's oxygen level at rest was 100 but with movement oxygen level went down to 70 to 80 percentage and her heart rate went up to 100. They treated her with IV (intravenous) saline drip on the first day in the hospital and nothing was given orally for the tests. They offered heparin and steroids but the patient declined. She will also be seen by a pulmonary specialist. At the time of reporting the patient was in the hospital. The action taken with covid-19 vaccine ad26.cov2.s was not applicable. The patient recovered from sweats, chills, headache, muscle aches all over the body, and low grade fever on 11-AUG-2021, and sore arm for 1 week, and burned intensely at the time of injection on 16-AUG-2021, had not recovered from chronic chest tightness, and labored breathing upon movement, and the outcome of with movement oxygen level went down to 70 to 80 percentage was not reported. This report was serious (Hospitalization Caused / Prolonged).; Sender's Comments: V0: 20210846641 -covid-19 vaccine ad26.cov2.s- chronic chest tightness, labored breathing upon movement, with movement oxygen level went down to 70 to 80 percentage. 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).