A plant-based cancer vaccine that kick-starts the immune system and can be tailored to target specific tumor types shows promise, according to U.S. researchers who tested the vaccine on 16 people with incurable follicular B-cell lymphoma.

More than 70 percent of the patients developed an immune response and none of them showed any significant side effects, Agence France-Presse reported. The study appears in the journal Proceedings of the National Academy of Sciences.

"The idea is to marshal the body's own immune system to fight cancer," said study senior author Ronald Levy of the Stanford Medical Center. "We know that if you get the immune system revved up, it can attack and kill cancer."

He and his colleagues are the first to test a plant-based cancer vaccine on people, AFP reported. It's not yet clear whether the immune response triggered by the vaccine is sufficient to destroy cancer.