Project Summary The main goal of the parent grant is to develop interferon-modulated vaccines against HIV. The proposed research will follow up on the same unifying concept of our parent DP2 grant, but in addition, it will consider the effect of boosting with a heterologous vaccine. Bakare has observed that boosting with a heterologous vaccine regimen enhances the efficacy of vaccines (manuscript in preparation). The preliminary data shown below is with SARS-CoV-2 vaccines, but it demonstrates a potentially novel and universal strategy to improve viral vaccines against HIV and other infectious agents that affect PWID. Improving vaccine efficacy is also critical to improve the lives of PWID.