A cancer vaccine seemed impractical. And yet! We recently discovered messenger RNA (mRNA) vaccines with the Covid-19 epidemic. This innovative vaccine production technique has indeed aroused mistrust among many of us. Yet it paves the way for new vaccines that could revolutionize the medical world and in particular the fight against cancer.
A new cancer vaccine
The company BioNTech, which developed the first mRNA vaccine against Covid-19, has just announced entry into phase II of a clinical trial focusing on the development of a new cancer vaccine. It would be a question of providing a solution for the treatment of melanoma advanced, cancerous tumors of the skin. The objective of phase II clinical trials is to assess the efficacy, tolerance and safety of the cancer vaccine, called BNT111. The tests are done with patients with advanced melanoma. For these patients whose disease is incurable and on whom conventional treatments have failed, the arrival of such a vaccine is more than expected.
The BNT111 vaccine is based on the same principle as the mRNA anti-covid vaccine, but the objective here is to make cells produce a combination of antigens generally associated with melanoma in order to induce a strong immune response against cancer. . Melanomas in patients can express different tumor antigens. Initially, BioNTech targeted four, present in more than 90% of melanomas, but the advantage of this type of cancer vaccine is that it is totally customizable ! We can therefore envisage in the coming years the production of tailor-made vaccines in order to best target cancer cells in a particular individual. A revolution in the field of the fight against cancer is perhaps to be expected!
How does an mRNA vaccine work?
Messenger ribonucleic acid (mRNA) is an integral part of our body. Essential to our existence, this molecule is responsible for transmitting certain information encoded in our genes, in order to trigger the synthesis of proteins necessary for the proper functioning of our cells. Indeed, the genetic code essential for the synthesis of proteins is contained in the nucleus of each of our cells. But the production centers (ribosomes) are located outside this nucleus. Hence the need for a “messenger”, allowing the transmission of the information contained in our genome to the production units. The mRNAs are therefore ephemeral copies of the protein manufacturing plan that our cells need. Once the message is transmitted, the mRNA is quickly destroyed.
The mRNA vaccines make use of this mechanism, which is at work in our bodies every day. This technique is totally different from the “classic” vaccination which is based on injection of an attenuated or inactivated virus or some of its proteins, with the aim of triggering an immune response directed specifically against the pathogen. Our body will thus keep the memory of this infectious agent and will know how to defend itself quickly in the event of a new infection. In the case of messenger RNA vaccines, no protein of viral origin is injected, only their manufacturing plan, via an mRNA. Once in our body, the injected mRNA will enter our cells and transmit its message, which is to synthesize the viral protein. Following vaccination, our body therefore begins to synthesize proteins itself specific to a pathogen, which will be recognized and elicit an immune response in the same way as for a conventional vaccine.
The advantages of an mRNA vaccine
The mRNA contained in the vaccine will not pass through the nucleus of our cells, it will attach itself directly to the ribosomes, the production units. So there is no risk of interaction with our genome, which will not be modified or altered in any way. This technique has a definite advantage: mRNA vaccines are good. easier and faster to produce than conventional vaccines because they do not require the handling of live (attenuated) or inactivated viruses. They also do not contain adjuvants, unlike conventional vaccines, the use of which is often criticized because of the presence of aluminum for example. Although we still have little experience, mRNA vaccines seem to have very good efficiency. However, the fragility of mRNA makes it necessary to store vaccine doses at a very low temperature.
With all these good points, the door is therefore open for the search for new mRNA vaccines, in particular for the treatment of cancers.
Morgane Gillard, scientific editor