The development of cancer vaccines

Extract: In the late 19th century, William Coley of the Memorial Sloan-Kettering Cancer Center in New York noticed the rare occurrence of tumors appearing to improve spontaneously, usually following an infection. This led him to propose that the human immune system could respond to tumors. However, his experiments to prove this fact met with limited success. Studies building from these observations conducted in the 1960's, led to the proposal of a theory of "the immune surveillance of cancer" by Burnet. They suggested that vaccines could be produced to promote the immune system's ability to protect against tumors. Unfortunately, subsequent clinical trials and animal models (comparing cancer rates in normal and immuno-compromised subjects) did not show any differences, which was explained by the suggestion that tumors are too similar to normal tissue to be distinguished by the immune system.