Project Summary Significant research has gone into the development of a safe and effective vaccine for HIV-1. Although many strategies have been attempted; none has been successfully established. Even a partially effective vaccine could decrease the number of people who are infected with HIV, further reducing the number of people who can pass the virus on to others. By substantially reducing the number of new infections, we could eventually stop the pandemic. To date, the elicitation of broadly neutralizing antibodies (bNAbs) has proven extremely difficult to achieve which brought a lot of effort on the novel trimer design and modification. At the same time, it was found that induced HIV- specific CD8+ T cell responses could limit both the transmission and establishment of persistent viral reservoirs. All the evidence suggest that no individual factor will determine the ultimate success of a bNAb-inducing HIV-1 vaccine, which will likely require a combination of efficient precursor B cell priming, optimization of Env design and presentation, sustained heterologous Env boosting, a T cell-based strategy, and newly developed delivery systems or adjuvants. Adjuvants or delivery systems can stimulate different arms of the immune system and are vital components of subunit vaccines, especially in the case of poorly immunogenic envelope glycoprotein. Deliver systems can also be designed to address instability of mRNA-based vaccines. The goal of this program is therefore to overcome challenges with HIV-1 vaccination and deliver a safe and effective vaccine using a biocompatible, biodegradable, easily manufactured short carbon nanotube (CNTVac) platform. Env-trimer and mRNA encoding peptide will be antigens for delivery and will target generation of both humoral and cellular responses. A humanized mouse model and a non-human primate model will be used for immunogenicity and efficacy studies. As the novel non-viral gene transfer vector for HIV-1 vaccine delivery, we will establish methodology for potential GMP production and generate safety profiles under FDA requirements.