These dogs are getting a cancer vaccine. If it works, humans could be next.

Johnston says his vaccine, if it works, would prevent a broad range of cancers from ever developing by having the immune system attack cancerous cells early. And he wants it to cost between $100 and $500, about the same as most infectious disease vaccines.

To create the vaccine, Johnston and his team screened 800 dogs who had at least one of the eight cancers most often found in canines. They identified a few hundred neoepitopes that the tumors from all eight cancers had in common and used 31 to develop the vaccine. Neoepitopes are the parts of a cancer cell that the immune system can target.

“We anticipate if we vaccinate with these 31 components ahead of time, just like an infectious disease vaccine, the dog’s immune system will be prepared — pre-prepared to see a tumor and kill it,” Johnston says.