{"nct_id":"NCT04490499","title":"A Hepatitis B Vaccine Challenge Study After Previous Vaxelis® Vaccination (V419-013)","status":"COMPLETED","status_verified_date":"2022-07","start_date":"2020-09-02","start_date_type":"ACTUAL","primary_completion_date":"2020-12-29","primary_completion_date_type":"ACTUAL","completion_date":"2020-12-29","completion_date_type":"ACTUAL","phases":["PHASE3"],"tickers":["MRK"]}