Final answer:
Cancer vaccines come in two forms: therapeutic, for treating existing cancer by stimulating the immune system to attack cancer cells, and prophylactic, to prevent cancer by targeting related viral infections. Examples include sipuleucel-T and talimogene laherparepvec for therapeutic use.
Step-by-step explanation:
Cancer Vaccines: Therapeutic vs. Prophylactic
Cancer vaccines encourage the immune system to recognize and attack cancer cells. These vaccines work by producing antibodies for cancer cells, or by enhancing the body's immune response to such cells.
Therapeutic vaccines are given to people already with cancer; they are designed to stimulate the immune system to selectively attack existing cancer cells, employing strategies like enhancing TH1 function and promoting interaction with cytotoxic T cells.
Prophylactic vaccines, on the other hand, are administered to people without cancer; they are designed to prevent cancer from occurring. These typically target viral infections known to cause cancer, such as HPV and hepatitis B vaccines preventing cervical and liver cancers.
Some examples of therapeutic vaccines include the FDA-approved sipuleucel-T (Provenge) for prostate cancer and talimogene laherparepvec (T-VEC or Imlygic) for melanoma. These highlight the innovative approaches being taken, including using the patient's own cells or modified viruses to enhance the anti-cancer immune response.