{"nct_id":"NCT03953196","title":"A Study Exploring the Use of Vaccine and Antigen Challenges for Immune Monitoring in Healthy Participants","status":"COMPLETED","status_verified_date":"2025-01","start_date":"2019-04-08","start_date_type":"ACTUAL","primary_completion_date":"2019-12-26","primary_completion_date_type":"ACTUAL","completion_date":"2019-12-26","completion_date_type":"ACTUAL","phases":["EARLY_PHASE1"],"tickers":["JNJ"]}