CD8A and infection: We were particularly interested to determine if SIVΔnef vaccination would convert the previously described “too little, too late” CD8 T cell response observed in unvaccinated animals [22], [23] to an “enough and soon enough” response in which virus-specific CD8 T cells would constitute a resident or rapid responder population at the portal of entry to control infection there, or contain infection after virus spread to the lymphoid tissues.