Vaccines against cancer

Despite setbacks, attempts to harness the patient's immune system to fight tumor cells show promise in clinical trials
Philip Hunter

Author Affiliations

  • Philip Hunter, Freelance Journalist, 1London, UK

Vaccines have been medicine's most successful weapon against disease since their first use in the early 19th century; they have saved countless lives, drastically decreased mortality in particular among children and helped to eradicate smallpox, one of the greatest scourges of humankind. Vaccine research is still ongoing to fight HIV/AIDS, malaria and a range of other diseases, and it has recently yielded another efficient tool against human papilloma virus to protect women from virus‐induced cervical cancer.

Meanwhile, vaccine research has opened up a second front by applying vaccination as a therapy for people already suffering from disease, which is not susceptible to a preventative approach. Such therapeutic vaccines could work against both infectious diseases and cancer and some are already being used to treat infections. However, the strategy of harnessing the patient's own immune system to fight cancer, although it is appealing and theoretically possible, has been facing a number of roadblocks in clinical practice.

Therapeutic vaccination to treat an infection is only effective against pathogens with a relatively long incubation period, for otherwise the immune system does not have enough time to mount a proper response. One example is the zoonotic viral disease rabies, often caught from dog bites, which still causes thousands of deaths mostly in developing countries ( Effective vaccines against the virus have been available for more than 20 years but the cost of vaccinating all people at risk in developing countries would be prohibitive. A more cost‐efficient alternative is to administer the vaccine after potential infection, such as a dog bite, exploiting the fact that the incubation period for rabies varies between 2 weeks and 6 years.

It is, however, the theoretical possibility of curing cancer that has created the greatest excitement and interest in therapeutic vaccine research. In fact, therapeutic vaccines could become an alternative to …