Immunization Awareness Month: Unlocking the Potential of Cancer Vaccines for a World Immune to Cancer 

Disease prevention is an integral part of the collective health of our society. The COVID-19 pandemic was an acute reminder of this, and it remains true for all diseases, including cancer. 

There are several ways individuals can help decrease their risks of getting cancer – many of them are behavioral, such as maintaining a healthy diet and abstaining from smoking. Others are more medical in nature, like undergoing regular health screening for cancer or even getting vaccinated against human papillomavirus (HPV) to protect against cervical or other related cancers. Cancer vaccines are a type of immunotherapy that trains the immune system to identify cancer cells and subsequently eliminate them. This potent and promising tool can help countless patients, both presently and in the future. 

CRI’s Past and Present Impact on Cancer Vaccine Progress 

CRI has been involved in cancer vaccine research since the 1950s, when founding scientific director Lloyd J. Old, MD, demonstrated the tuberculosis vaccine Bacillus Calmette-Guérin (BCG) could thwart tumor expansion in mice. Over two decades later, former CRI grant recipient Alvaro Morales, MD, FRCSC, pioneered how BCG can be used to treat non-invasive bladder cancer. BCG became the first active FDA-approved immunotherapy treatment in 1990. 

CRI scientists have made several significant discoveries with cancer vaccine development in recent decades. Former CRI CLIP Ian H. Frazer, AC, FRS, FAA, professor with the faculty of medicine at University of Queensland in Australia, propelled scientific breakthroughs that led to Gardasil® becoming the first preventative cervical cancer vaccine. 

Though CRI scientists have made monumental discoveries with cancer vaccines, helping patients around the world in the process, the work continues. Several CRI scientists currently conduct research that could benefit future cancer vaccine development. 

“Our approach has been to administer immune stimulants directly into a patient’s tumor site to create the vaccine at the site, this approach is called in situ vaccination,” CRI Lloyd J. Old STAR Joshua Brody, MD, explained. “We have been fortunate to see numerous patients who, after receiving in situ vaccination at one site, have their tumors melting away throughout the body. Some of the best results have been in lung cancer, lymphoma, and breast cancer.” 

How do cancer vaccines work? 

The first vaccine targeted smallpox during the late 18^th century. Since then, numerous vaccines have saved hundreds of millions of lives from various disease outbreaks. However, cancer vaccines are more sophisticated than their counterparts for other diseases because similar cancer types can present unique properties from person to person, and the disease can disguise itself from the immune system. 

“The challenge to using vaccines for cancer is that unlike pathogens, which are inherently foreign, cancer cells are part of us,” Vinod Balachandran, MD, member of the David M. Rubenstein Center for Pancreatic Cancer Research at Memorial Slone Kettering Cancer Center, told CRI in April 2024.  

“In order to develop a cancer vaccine, we have to teach the immune system to exquisitely recognize the aspects of the cancer cell that are most foreign, while at the same time not teaching the immune system to start attacking ourselves.” Dr. Balachandran concluded. 

Broadly speaking, there are two categories for cancer vaccines: preventative and therapeutic.

Preventative cancer vaccines help people reduce their risk of cancers that occur due to viral infection. For example, HPV and hepatitis B virus (HBV) can lead to cervical or oral cancers. Vaccines such as Cervarix®, which targets the two HPV strains that cause most cervical cancers, is also approved by the FDA to treat other cancer types, such as head and neck.

The human immune system has an innate ability to recognize and attack harmful cancer cells, a dormant superpower immunotherapy can harness. Therapeutic cancer vaccines boost and leverage this ingrained reflex so immune cells can more easily locate and fight cancer cells. Therapeutic vaccines are currently being produced to inhibit cancer recurrence.  

“There are a number of ongoing cancer vaccines in research, including clinical trials,” Kunle Odunsi, MD, PhD, FRCOG, FACOG, director of the University of Chicago Medicine Comprehensive Cancer Center and CRI Scientific Advisory Council associate director said. Dr. Odunsi also serves as the biological sciences division dean for oncology and professor of obstetrics and gynecology at the University of Chicago. “Two major approaches are currently being tested in a majority of clinical trials: neoantigen vaccines that target genetic alterations that are exclusive to cancer cells but not normal tissues and the use of newer methods of manufacturing dendritic cells for vaccination in order to generate more important immune responses.”   

Neoantigen vaccines that Dr. Odunsi refers to represent the next step in cancer vaccine research. These vaccines use a tailor-made approach to fight cancer with an individualized, precision-based approach to develop the vaccines that target antigens – foreign proteins on cancer cells that the immune system can recognize and target. The way these vaccines are developed is by removing a tumor sample from the patient, identifying the neoantigens present in the tumor, and developing a personalized vaccine using the neoantigen data from person’s own cancer cells. The vaccine is then administered to the patient and becomes the catalyst for a strong immune response against their cancer. 

Thanks to the tireless contributions of CRI scientists, cancer patients, caregivers, and others, we are hopeful the progress made by cancer vaccine technologies can help create a world immune to cancer.