In an effort to improve the global clinical development of new medicine, adaptive designs have been gaining popularity in all phases of clinical development. In general, adaptive designs are developed to increase the flexibility of clinical trials, such as modification of sample size, dropping ineffective treatment arms, enriching study populations, or early stopping for either futility or efficacy. Such designs are useful in both the “learning” and “confirming” phases of clinical development. In this presentation, we will highlight some areas that adaptive designs are practical and efficient in vaccine clinical development. We will also emphasize the statistical guidance and scenario planning in assessing operating characteristics of trial designs with adaptation. Examples will be used to illustrate the design features.