The next big advance in cancer treatment could be a vaccine.

After decades of limited success, scientists say research has reached a turning point, with many predicting more vaccines will be out in five years.

These aren’t traditional vaccines that prevent disease, but shots to shrink tumors and stop cancer from coming back. Targets for these experimental treatments include breast and lung cancer, with gains reported this year for deadly skin cancer melanoma and pancreatic cancer.

“We’re getting something to work. Now we need to get it to work better,” said Dr. James Gulley, who helps lead a center at the National Cancer Institute that develops immune therapies, including cancer treatment vaccines.