Effective Targeted Delivery of RNA-based Vaccines and Therapeutics: RNA-based therapeutics have shown the potential to silence HIV effectively upon direct transfection in vitro, but delivery into cells in vivo is still unsatisfactory. Vector-based (lentivirus, adeno-associated virus) delivery to quiescent cells has proven inefficient, and the vectors themselves pose a risk to the host. To enhance stability and to confer vehicle-free delivery, RNA-based drugs have been chemically modified to improve their properties. Progress was also made in chemical-based delivery strategies, e.g., liposomes, molecular-sized chemical conjugates, and supramolecular nanocarriers. An additional advantage is that RNA can be produced in vitro in a cell-free manner, avoiding safety and manufacturing issues associated with cell culture. Despite these advances, nucleic acids per se are relatively large, negatively charged polymers, and significant clinical challenges from the standpoint of delivery to cells still persist. The primary goal is to develop improved platform technologies for the delivery of RNA into specific cells and tissues to improve the efficacy of HIV vaccines or therapeutics.