Design, Analysis, and Interpretation of Ebola Vaccine Efficacy Trials in West Africa

• Activity Number: 462
• Type: Invited
• Date/Time: Wednesday, August 12, 2015 : 8:30 AM to 10:20 AM
• Sponsor: ASA
• Author(s): Ira M. Longini* and Natalie Dean
• Companies: University of Florida and

Abstract

In this talk we will describe, the design, analysis and interpretation of the Ebola vaccine trials that were planned in Liberia (randomized control trial), Sierra Leone (stepped wedge), and Guinea (ring vaccination). We will go through the statistical analysis planned for each, and what outcomes were expected. We will then describe, in detail, the ring vaccination trial in Guinea that went into the field in March 2015. The rings are close contacts of index cases, with rings randomly receiving vaccine immediately or in a delayed fashion. Comparison of Ebola incidence in the early vs delayed rings forms the basis for the estimation of vaccine efficacy and statistical tests concerning vaccine efficacy. We will explore the important operational and statistical issues with respect the ring vaccination trial.