One of the main causes of blindness in the world, especially after 60 years. In France, it affects nearly a million people, often forced to a heavy treatment: regular injections directly in the eye. These gestures, as impressive as it is painful at the idea, weigh on the daily life of patients and the care system. A team of Californian researchers has tested an unprecedented vaccine based on messenger RNA technology, already widely known thanks to the Vaccines against the COVVI-19. Their objective: to find a simpler and lasting alternative to these binding injections. The first results, published in the journal Vaccinatedarouse real hope.
DMLA, a disease that requires binding injections
The DMLA gradually destroys the Macula, a tiny area of the retina which allows you to read, drive or recognize faces. This pathology exists in two forms. The so -called “dry” form, more frequent, slowly evolves and leads to a progressive loss of central vision. The “wet” form is more aggressive: it is caused by the growth of abnormal blood vessels in the eye, a condition called neovascularization. These blood vessels let the accumulation of liquid flow in the retina, which gradually leads to a loss of vision in the absence of treatment.
Today, patients with wet form should regularly receive injections of anti-angiogenic drugs that stop the formation of blood vessels directly in the eye. . This treatment prevents anarchic growth of blood vessels but requires a constant repetition, sometimes every month, which is physically and psychologically trying.
An RNA vaccine tested on mouse models
It is precisely to lighten this burden that a team led by Masayo Uchida, assistant professor in pharmaceutical sciences at the University of California in Irvine, designed an experimental vaccine. Based on messenger RNA technology, it was tested on two mouse models developing an experimental AMD. Usually, messenger RNA vaccines provide instructions to the body so that it generates antibodies against pathogens. In this context, the vaccine introduces mRNA which code for alpha-2-glycoprotein 1 rich in leucine (LRG1), a protein involved in angiogenesis and presents in high quantities in people with AMD. The body then produces antibodies which are specifically attached to LRG1 and neutralize it.
The vaccine was tested on two murine models of the disease. After only two intramuscular injections administered 14 days apart, the two models showed a strong immune response which significantly reduced the abnormal growth of blood vessels in the retina. The effects were visible from the week following the first dose.
© Institute of Science Tokyo
The vaccine turned out to be sure. He did not disturb the normal growth of blood vessels, did not damage the healthy retinal tissue and did not trigger harmful immune reactions in other mice organs. At the same time, the treatment has proven as effective as the classic vascular endotheal (VEGF) growth anti-factothelial (VEGF) drugs without however presenting their major drawbacks.
Professor Satoshi Uchida of the advanced nanomedical engineering department of science Tokyo declares: “To our knowledge, this is the first study demonstrating that an mRNA vaccine can remove pathological neovascularization in animal models (…) The effects of LRG1 mRNM vaccination on the reduction of endothelial and microglial cells were comparable to those of anti-vegf antibody treatment. Unlike conventional treatments requiring repeated intravitrean injections, this vaccine could offer long -term benefits with a single intramuscular dose, thus potentially reducing the therapeutic load for patients“.
Towards a simpler alternative than intraocular injections
If the results must still be confirmed in humans, the idea of a vaccine constitutes a symbolic and concrete advance. This more practical and less invasive option could transform the lives of thousands of patients who live today to the rhythm of ophthalmological meetings and the fear of the needle.
The researchers remain cautious: the transition from an animal study to a human clinical trial represents a long path. But for the medical community as well as for patients, hope is very real.
A future treatment in the form of vaccine, administered more rarely and less intrusive, could release the weight of repeated injections.