Updated:11/17/2020 12: 25h
The vaccinations are trendy. We are in the middle of the flu vaccination season. We hope with hope favorable news about the vaccine to combat the Covid-19. The pseudoscientific discourses of those who deny the value of vaccines, once accepted by many, are now being silenced by good sense. The situation does not invite frivolity. And in this favorable environment for vaccines it is worth asking, Can we also get vaccinated against cancer?
Vaccines teach our immune systems to recognize and eliminate dangerous agents. This reduces the risk of contracting a disease by activating our natural defenses against the invading organism.
Protection against diseases such as measles, chickenpox, flu and, of course, Covid-19 immediately comes to mind. All of them infectious diseases. The World Health Organization recognizes more than 25 types of vaccines to prevent many other potentially fatal infectious diseases. Immunization is estimated prevents two to three million deaths each year.
What might seem surprising is learning that some vaccines are used to prevent the development of cancer. Two of these vaccines are in common use today. The human papillomavirus vaccine targets strains of this virus that cause cervical or throat cancers, among others. The hepatitis B vaccine prevents some cases of Liver cancer. Both are vaccines that protect against the appearance of cancer, that is, they have a prophylactic function.
Lung Cancer Vaccine
Can we ever have a prophylactic vaccine to prevent the deadliest cancer we know of, lung cancer? It seems unlikely, since lung cancer is not caused by a virus or bacteria. This disease, from which more than two million people die annually in the world (more than 20,000 in Spain), is caused by damage to the genetic material caused by non-infectious agents, mainly the tobacco carcinogens.
Each lung cancer is an entity with its own genetic alterations. None of these changes is common for all lung cancers. Therefore, it does not seem an easy task to develop a vaccine against an element common to all lung cancers.
But this does not mean that we have to give up a vaccine against lung cancer.
There are also therapeutic vaccines, designed so that the immune system is capable of eliminating tumors already present in the body. The existence of these vaccines is almost as old as that of the prophylactic vaccines.
The Father of Cancer Immunotherapy
In the late 19th century, William Coley observed that febrile infections in some of his patients were associated with regression of the cancer. From these observations he deduced that cancer patients could be treated with therapies that stimulate the immune system against tumors. Dr. Coley is considered the father of cancer immunotherapy.
We may never be able to prevent lung cancer with a vaccine, but thanks to immunotherapy, the day may come when a vaccine helps fight an existing lung cancer. It’s about getting teaching the immune system how to recognize cancer cells as foreign, which needs to be removed.
Some patients with prostate cancer or bladder cancer are already treated, today, with therapeutic vaccines. But this possibility does not yet exist for lung cancer patients, beyond the context of clinical trials.
The latest scientific advances invite optimism
Several attempts have already been made to obtain a therapeutic vaccine against lung cancer. So far, the evaluated vaccines have not demonstrated a clear clinical benefit. However, the latest scientific advances invite optimism.
The development of mass sequencing technologies it is allowing the design of vaccines adapted to each patient. Today it is possible to generate genetically modified immune cells with better antitumor properties, the so-called cells CAR-T. Finally, the vaccines can be combined with drugs such as anti-PD-1 / PD-L1 and anti-CTLA-4 antibodies that enhance the antitumor response.
The technology is there. Now it needs to be put to work to demonstrate its clinical utility. Numerous clinical trials in lung cancer patients using vaccines based on the latest technological and knowledge advances. They are vaccines developed individually, for each patient. A clear example of personalized medicine.
The development, in the 20th century, of vaccines for diseases such as measles, smallpox, polio, mumps or rubella saved, and continues to save, countless lives.
Why not imagine that in the 21st century we will develop vaccines against the main types of cancer? To do this, let us make a firm commitment to biomedical research and trust its fruits.
Rubén Pío. Director of the Solid Tumors Program, CIMA, University of Navarra.
This article was originally published on The Conversation.