This roundtable discussion will focus on the potential use of adaptive design trials (ADTs) for evaluating efficacy of preventive vaccines. To date there have been very few such designs for vaccines, except for well-understood adaptive designs, such as group sequential and interim adjustment of sample size, etc. Recently, there has been discussion about expanding the use of ADTs, especially in the field of HIV vaccine development. This discussion will highlight potential advantages and disadvantages of the use of such designs in this product area. The following questions will be the focus of the discussion.

1. What advantages do ADTs offer in the development of preventive HIV vaccines?

2. What challenges do ADTs pose in the development of preventive HIV vaccines?

3. Considering the advantages and challenges, what recommendations can be made for use of ADTs in the development of preventive HIV vaccines?