Vaccines designed to turn the immune system against cancer have been logically constructed and tested against many cancers. Almost all have failed or shown minimal effect. They spark creation of killer T cells against the cancer, but generally have little effect on tumors, both in patients and mouse models.
Willem Overwijk, Ph.D., and colleagues at MD Anderson discovered that a common vaccine component is sabotaging treatment. The mineral oil IFA lingers at the vaccine site for months and attracts the main T cell attack there, diverting them away from the tumor. The team found substituting a saline solution for IFA reversed this effect, leaving minimal T cells at the injection site while concentrating them on destroying the tumor.
A clinical trial is planned this year.