Decades-Old Breast Cancer Vaccine Triggers Durable Immune Memory, New Boosting Approach Emerges

Researchers studied survivors from a decades-old breast cancer vaccine trial and found they retain powerful CD27+ immune memory years later. In mice, combining a CD27-activating antibody with a HER2-targeting vaccine dramatically increased tumor rejection, largely via CD4+ T cells and, with additional CD8+ T-cell support, boosted efficacy to near 90%. The findings suggest CD4+ T cells can drive lasting anti-tumor immunity and that a single CD27 boost alongside vaccines could enhance cancer immunotherapies in humans.