Figure 1. A framework for HIV vaccine development.

Two parallel pathways in an HIV vaccine development framework can be envisaged. One pathway (which leads to a regional vaccine strategy) builds on the poxvirus prime protein–subunit boost vaccine concept tested in the RV144 clinical trial (12). Such vaccines would test the ability of additional boosts and adjuvant formulations to improve the durability of protection observed in RV144 and evaluate performance in new risk and geographic populations. The second pathway (which would lead to a global vaccine strategy) seeks to evaluate universal or globally effective HIV vaccines using novel HIV vaccine types (including rare serotype human adenoviral vectors), insert design, adjuvants, and clinical study designs.