Some Cancer Vaccines Successful in Early Clinical Trials

Ruwaida Dhala, BSc, MSc

Vaccination has one of the greatest impacts on disease prevention. Most vaccines generate protective immune responses against a pathogen, preventing disease initiation. Often the immunity generated by vaccines to specific pathogens is lifelong. Preventative vaccines are not effective in cancer prevention, however, mostly because cancer antigens elicit poor immune responses. For this reason many cancers evade the immune system. Cancer vaccine strategy focuses on eliciting anti-tumour responses in patients that are already afflicted with cancer. These vaccines will presumably prevent cancer progression and reoccurrence rather than prevent cancer initiation.

In order for the body to mount an immune response, the invading pathogen, or components of it, must be exposed to the immune system. There are two major components of the immune system, humoral and cellular. Humoral immunity is involved in the generation of antibody responses. These antibodies are usually directed against extracellular pathogens such as bacteria. Most preventative vaccines rely on this arm of the immune system.