Vaccines provide the immune system with information to recognise and fight threats before they appear in the body. Although we associate vaccines with infectious diseases the cancer field is growing more effective. In the1890s William Coley reported that injecting bacterial toxins could shrink tumours. Then the first cancer vaccine was developed in 1980. So how do cancer vaccines vary from the vaccines we know already?
Unlike bacterial or viral threats, cancer cells don’t strike the immune system as a threat. This poses a challenge to the development of cancer vaccines, so what are we working with and where do we go from here?
- Prophylactic Vaccines are taken to lower the risks of cancer from viral infections. Cancer can be caused by HPV or HBV for example, so anticipating and addressing these viruses is a way of reducing the likelihood of cancer.* So far four of these have been approved in the United States by the FDA.
*For information on the HPV cancer vaccine from Dr Andrew Ishizuka book your tickets to the World Vaccine Congress in October 2022 here.
- Therapeutic Vaccines respond to the active threat in the body. The goal is to reduce the tumour and create a lasting memory against tumours without adverse reactions. Each unique tumour requires sophisticated approaches. We are now able to identify targets that distinguish cancer cells from healthy cells. These can be proteins produced in excess, such as prostatic acid phosphatase, which is expressed by prostate cancer cells. In response to the identification of this excess protein, a vaccine was approved by the FDA in 2010. Another target area for is virus-derived protein, expressed by cancer cells that developed from a viral infection.
- Personalised Neoantigen Vaccines are being evaluated in clinical trials to establish their effectiveness alone and in combination with other treatments. Tumours display targets that result from mutations, neoantigens uniquely expressed by cancer cells. By addressing immune responses towards the tumour cells and avoiding healthy cells, side effects can be reduced. Dr Julie Bauman of the University of Arizona Cancer Centre is co-leading a clinical trial testing a personalised mRNA vaccine in combination with an immune checkpoint inhibitor. Testing is on patients with advanced head and neck cancer. The study is sponsored by Moderna, which produces each vaccine in about 6 weeks. Results were positive, resulting in the study’s expansion. However, according to recent reports, algorithms produce several possible candidates, and only a few trigger antitumour responses. There is more work to be done.
Dr Hans Keirstead, CEO of AIVITA Biomedical, will speak at the World Vaccine Congress in Barcelona, October 2022, with an update on vaccine technology for cancer and Covid-19. To get your tickets head to this link.
