Observations that stronger specific CD4/CD8 immune responses with CD4+ T-helper (TH1) cytokine profiles, for example, are found more frequently in patients with self limiting viral infections than in those who develop chronic viral carriage [10,11] has directed attention to the balance of CD4+ TH1/TH2 lymphocyte responses and resulted in attempts to enhance immune responsiveness therapeutically [12,13], in the belief viral clearance will be enhanced long term by these therapies. Here, CD4 is linked to viral infectious disease.