JACKSONVILLE, Fla. (CBS Local) — A definitive cure for cancer has remained elusive despite years of steady advancements in treatment.

But a team of researchers on the Mayo Clinic’s Florida campus are studying a new anti-cancer vaccine that would help the body resist the return of an aggressive form of breast cancer.

The vaccine would be used in combination with Trastuzumab, an immune-stimulating drug given to women following surgery to remove a HER2 tumor.

HER2-positive breast cancer is a breast cancer that tests positive for a protein called human epidermal growth factor receptor 2 (HER2), which promotes the growth of cancer cells. In about 1 of every 5 breast cancers, the cancer cells have a gene mutation that makes an excess of the HER2 protein.

If it works, researchers say the vaccine would address the return of the cancer, which can be hard to treat once it spreads to other parts of the body.

Trastuzumab works by activating the immune system’s B-cells, which look for and attack breast tumor cells with HER2 proteins on the surface.

The new vaccine stimulates another group of cells in the immune system, long-lasting T-cells that “remember” the proteins and promote resistance to the recurrence of the disease.

“The vaccine provides a prevention strategy to deter cancer reformation,” says Dr. Keith Knutson, a Mayo Clinic immunologist who is principal investigator of the study. “The body’s T-cells and B-cells synergize with each other for a strong, durable, immune response.”

Future research will determine if the vaccine is effective against the recurrence of HER2 breast cancer.