摘要
1.Introduction A vaccine clinical trial examines the effects of a vaccine on human volunteers in terms of safety,immunogenicity,and clinical efficacy through three distinct stages[1].In general,phase 1 studies focus on safety and reactogenicity,while phase 2 studies attempt to establish an immunogenicity proof of dose range,dosage,and immunization procedure(sometimes even efficacy data).Large phase 3 studies are designed to evaluate whether the dosing and vaccination schedule can deliver the desired protection efficacy with an acceptable safety profile[2].A phase 3 vaccine clinical trial provides indispensable efficacy data to support a vaccine that has been issued with licensure.
