A T-cell vaccine is a vaccine designed to induce protective T-cells.
T-cell vaccines are designed to induce cellular immunity. They are also referred to as cell-mediated immune (CMI) vaccines.
It is thought that they can be more effective than conventional [B-cell] vaccines for protection from microbes that hide inside host cells, and viruses (such as HIV or influenza) that mutate rapidly.
T-cell vaccines underwent clinical trials for HIV/AIDS.
As of July 2012 none have been approved.
References
T-cell vaccine Wikipedia(Text) CC BY-SA