A therapeutic mRNA vaccination can help the immune system recognize and eliminate a tumor, preventing possible recurrences — and with minimal side effects. There is still no vaccine against cancer, but rather against infections capable of leading to the development of certain types of tumor. This is the case, for example, with the dangerous cervical cancer. Behind this serious disease is the human papilloma virus (HPV), and there is a vaccine against it. Its mere existence can be considered a major breakthrough.
This preventative vaccination has been around since the early 2000s and protects against high-risk HPV infections. The infection itself does not cause cancer, but if the virus permanently implants itself in the cells of the mucous membrane, it can end up triggering pre-cancerous stages.
Another example of a preventive vaccine is against the hepatitis B virus, which protects against liver tumors that can develop from chronic hepatitis B. According to data from the German Cancer Information Service, around 4% of all cancer cases in industrialized nations are attributed to infections by viruses or bacteria. In developing countries, the proportion is even higher.
In addition to these two recommended preventive vaccines, there are therapeutic vaccines that have been intensively analyzed. With them, it is possible to treat existing cancer. In this case, mRNA vaccines can train the immune system, for example, to fight cancer cells, teaching it to recognize and eliminate them quickly and individually. And this with minimal side effects. To do so, however, it is necessary to fulfill some prerequisites.
“As the science currently stands, mRNA vaccines are primarily an option when tumor tissue has already been largely removed from the body through an operation, for example. So with an mRNA vaccine in combination with other active ingredients , you have a better chance of eliminating cancer cells that may have remained in the body and could lead to a recurrence”, explains Suzanne Weg-Remers, from the Cancer Information Service.
In the best case scenario, therefore, the mRNA vaccine offers even more chances of a cure for cancer patients. Based on the same technology used against the Sars-CoV-2 virus during the Covid-19 pandemic, the mRNA vaccine allows doctors to individually adapt therapy according to the characteristics of each tumor.
The role of tumor antigens
Ideally, cancer cells carry on their surface typical characteristics that are rare or even non-existent in healthy cells. These tumor antigens, as they are called, serve as the basis for the development of vaccines against cancer cells. The patient then receives a vaccine that triggers an immune response against tumor antigens. The goal is to teach the immune system to defend itself against cells with these specific antigens.
Through the therapeutic mRNA vaccine, researchers have already been able to record the first successes in preliminary clinical studies against melanoma.
“For 2024, an international clinical study with 1,000 patients on mRNA therapy for malignant melanoma, i.e. skin cancer, is planned. It will be the basis for approval [da vacina]”, says Weg-Remers.
Other types of cancer that will also be analyzed by researchers are colon and lung cancer, both among the most common manifestations of the disease.
Vaccine is not a magic solution
“There are more than 200 types of cancer and many other subtypes that differ in their molecular properties. Now finding the ‘magic formula’ capable of preventing or treating all these different types through a vaccine is very difficult”, ponders Weg-Remers.
According to data from the Cancer Information Service, almost half a million people fall ill with cancer every year in Germany alone. In 2021, almost 230,000 died from the disease. Behind the statistics and each number are people, with their personal destinies and all the anguish that the word “cancer” triggers.
Despite all the advances so far, the researchers are keen to emphasize that the development of the vaccine is still at an early stage. Preliminary results indicate that vaccination may be effective against cancer, but there are still many large clinical trials that compare new approaches with conventional treatments.
Furthermore, the conditions of the disease are quite diverse: if in some cases, for example, the tumor has been removed and there are only a few isolated cells left to fight, this is a completely different condition than when there is already metastasis.
“I believe that cancer treatment will continue to be a treatment in which different methods are combined to achieve good results”, says Weg-Remers.