Thus, anti-Tat Abs are essential to neutralize the Tat and Env complex entry and virus infection, and the presence of both anti-Env and anti-Tat Abs, as occurring in Tat vaccinated HIV infected patients or in Tat/Env vaccinated monkeys, is required to block HIV entry and infection (Fig. 16). This evidence concerns the gene ERVW-1 and viral infectious disease.