CD8A and infection: The hypothesis underlying these studies was that SIVΔnef vaccination might protect in part by converting the “too little and too late” CD8 T cell response to these immunodominant epitopes in unvaccinated animals [22], [23] to an “enough and soon enough” response in the vaccinated animals, sufficient to contain infection at the portal of entry or the lymphoid tissues (LTs) to which infection subsequently spreads.