Compositions including a therapeutically effective amount of an HIV immunogen in combination with an agent that stimulates the Ras pathway, wherein the agent is not an aluminum salt, are disclosed. Methods are also disclosed for inducing an immune response to HIV, and/or to inhibit or treat HIV infection, in a subject, using an HIV immunogen and an agent that stimulates the Ras pathway. Methods also are disclosed for determining if an immunogenic composition will induce a protective response, and/or to determine if an immunogenic composition is of use to prevent or treat an HIV infection. The methods including determining if the immunogenic composition increases the level of one or more components of the Ras signaling pathway.