IFNA1 and severe acute respiratory syndrome: Collectively, the marked expression of IFN-mediated responses in the lungs of viremic SARS-CoV infected ferrets and not reinfected ferrets further asserts that proinflammatory IFN responses complement the acute phase of SARS and that resolution of IRG activity is associated with priming of an anamnestic response that will neutralize SARS-CoV reinfection without reinitiating acute inflammation.