Scientists in the United States said on Monday they have developed a vaccine that attacks tumors in mice, a breakthrough they hope will help fight breast, colon, ovarian and pancreatic cancer in humans.

Although studies on mice often do not translate directly into remedies that work for human subjects, researchers are hopeful because of the strength of the vaccine and the particular approach it takes.

"This vaccine elicits a very strong immune response," says study co-senior author Geert-Jan Boons, a professor of chemistry and a researcher in the University of Georgia Cancer Center.

"It activates all three components of the immune system to reduce tumor size by an average of 80 percent."