Given the scope of the worldwide health problems caused by the acquired imm
unodeficiency syndrome, tuberculosis, and malaria, it is imperative that va
ccines be developed to prevent these infections. Recent advances in the und
erstanding of these diseases suggest that T-lymphocyte-mediated immunity is
important in containing these infections. The application of novel vaccine
technologies for eliciting this type of immunity promises to provide succe
ssful vaccines for controlling the spread of these deadly infections.