Fourth, the CD8+ CTL impairment observed in the study was a lung-specific phenomenon, as no impairment was observed in the spleen under conditions of local infection in the lung (i.e. influenza, RSV), localized dermal infection (i.e. VV-M2 administered ID), or disseminated infection (i.e. VV-M2 administered IN). This evidence concerns the gene CD8A and infection.