To understand how the immunomodulatory properties displayed by Tat on APCs and T lymphocytes affect, in vivo, the overall immune responses against a viral infection, C57BL/6 mice were infected intravaginally (i.v.)with wild type HSV1 (strain LV) with or without the Tat protein administered at the time of infection by the subcute route. The gene discussed is TAT; the disease is viral infectious disease.