Will a vaccine one day protect women from breast cancer? Researchers at the Cleveland Clinic certainly hope so, and they’re working to make this vision a reality.

Several years ago they developed a potential breast cancer vaccine and tested it in mice with a genetic predisposition to the disease. A 2010 study published in Nature Medicine detailed the promising results. The researchers found that the vaccine effectively prevented tumors in some of the mice. In others that already had tumors, it slowed tumor growth.

According to the researchers, the vaccine was designed to target a protein typically found in tumors caused by triple-negative breast cancer. This form of the disease is one of the most aggressive and deadly. The theory is that introducing this protein into the body via immunization will entice the immune system to see the protein as foreign and attack it. That might stop triple-negative breast cancer before it ever gets started.

But there’s a catch: Women who are lactating produce this protein normally, without any cancer present. To avoid negative effects from a woman becoming pregnant and lactating after vaccination, only those past child-bearing age should receive the drug.

There’s still a long way to go before we know whether this vaccine will work as its inventors hope. A company started by the Cleveland Clinic is developing a version of the vaccine to test in humans. Once that’s done, the U.S. Food and Drug Administration will have to give approval before trials in people can begin. After this, the multi-stage trial process will likely take a few years. That will reveal whether the drug is truly effective and safe.

Wouldn’t it be wonderful to have this new weapon in the fight against breast cancer? As the saying goes, “An ounce of prevention is worth a pound of cure.”