Moreover, these asymptomatic individuals are known to have a diminished parasite-specific CD4+ proliferative and cytokine (particularly IL-2, IFN-γ) responses; with longstanding infection, this modulated parasite-specific response appears to extend to non-filarial (bystander) antigens including orally- and parenterally delivered vaccines (13–26). The gene discussed is CD4; the disease is infection.