Describe the concept and typical purpose of therapeutic cancer vaccines.

• A. Vaccines designed to treat existing cancer by stimulating an immune response against tumor antigens, often using peptides, dendritic cells, or viral vectors
• B. Vaccines to prevent cancer initiation
• C. Vaccines to deliver chemotherapy
• D. Vaccines to immunize against viral infections that cause cancer

Answer: (A)

Therapeutic cancer vaccines aim to treat existing cancer by getting the immune system to recognize and attack tumor cells. They present tumor-associated antigens to the immune system using approaches like peptides, dendritic cells loaded with antigen, or viral vectors that encode the antigen, with the goal of activating cytotoxic T cells that can kill tumor cells and help sustain an anti-tumor response.

This is different from vaccines that prevent cancer initiation by stopping infections that can cause cancer, and from strategies that deliver chemotherapy. It’s also not about vaccines that immunize against viruses that cause cancer in general, though preventing those infections can reduce cancer risk.