CD4 and infection: Our results provide clear evidence that (1) P. falciparum-specific CD4+ T cells are maintained in the absence of continual exposure to the parasite, (2) continual exposure to P. falciparum induces a strong immunoregulatory response capable of dampening infection-associated inflammation, and (3) P. falciparum-specific CD4+ T cell proliferation (following in vitro stimulation) is significantly enhanced after a period of minimal exposure.