An effective HIV vaccine has yet to be created, and maybe one never will. Scientists working on protective vaccines have mountains of problems with the virus' slippery nature, but perhaps most unnerving is that a vaccine-primed immune system might be more susceptible to infection. Boosting the HIV-specific helper cells may be giving the virus more factories in which to reproduce.
T helper (Th) cells have a "dual role as target cells for infection, as well as being important mediators of the host immune response," says Mark Feinberg, professor of medicine at Emory University in Atlanta. Whether aiming more for humoral (antibody-based) protection or cellular protection, antigen-specific CD4+ T cells are "critically important for the individual's ability to mount a strong, durably effective immune response to the virus," explains Feinberg. Activated Th cells produce the cytokines and interact with the cell-surface receptors that prompt B cells to produce antibodies; they also ...
