Decades-Old Cancer Vaccine Reveals Path Toward Long-Term Tumour Immunity

Women treated with an experimental breast cancer vaccine in the United States have remained alive more than 20 years later, highlighting a breakthrough in long-term immune protection against metastatic cancer.

“We were stunned to see such durable immune responses so many years later,” said Zachary Hartman, Associate Professor of Surgery, Integrative Immunology and Pathology at Duke University School of Medicine.

Researchers found that the women retained CD27+ immune memory cells, which help the body recognise and fight cancer over time. Laboratory experiments combining a HER2-targeted vaccine with a CD27-activating antibody eliminated tumours in nearly 40% of mice, compared with 6% with the vaccine alone, and adding further immune support raised tumour rejection rates to nearly 90%. The findings suggest that strengthening CD4+ helper T cells, often overlooked in cancer therapy, could improve vaccines and support treatments such as immunotherapy and antibody-drug therapies, potentially advancing more durable cancer-survival strategies.