Infection with the Epstein-Barr virus (EBV), which affects more than 95% of the world’s population, is the cause of infectious mononucleosis, which is popularly known as kissing disease because one of its main forms of contagion is coming into contact with the saliva of an infected individual (by kissing him or sharing utensils impregnated with it, such as cutlery). This virus has also been associated with some types of cancer, such as stomach cancer or Hodgkin’s lymphoma, and recently some studies have linked it to the development of multiple sclerosis (MS), a chronic disease suffered by around 55,000 people in Spain.
A vaccine capable of preventing EBV infection would be very beneficial to protect public health and a group of scientists from the pharmaceutical company Sanofi has just developed an experimental vaccine against this virus. The study in which they have tested the new drug has been carried out with animals and in it they have verified that it was able to induce an immune response against EBV and generate protective antibodies.
The findings, which have been published in Science Translational Medicine, constitute a starting point to create what could become the first effective vaccine in humans to prevent infection by this virus and the diseases it causes.
The vaccine prevents the EBV virus from entering cells
The Epstein-Barr virus infects B lymphocytes – a type of immune system cell – and epithelial cells, which are responsible for protecting organs, and the mechanisms it uses to penetrate these cells vary, making it difficult to develop a effective vaccine against all its forms of action. Now, Sanofi researchers have managed to identify four of the ‘locks’ that the virus uses to penetrate cells and this has allowed them to create a vaccine aimed at blocking them to prevent infection.
When testing the vaccine in mice, ferrets and macaques, it was found that it stimulated the creation of neutralizing antibodies that prevented the Epstein-Barr virus from penetrating cells
The authors of the study have tested their new vaccine in mice, ferrets and macaques, and have observed that it stimulated the creation of neutralizing antibodies in the animals that prevented the virus from penetrating the cells. During the trial they also isolated antibodies generated by mice that had been given the vaccine and injected them into unvaccinated mice that were exposed to the virus and found that these antibodies protected them from Epstein-Barr-associated lymphomas.
Although the results are promising, it is necessary to test the drug in humans, and although it is not difficult to verify if the vaccine protects against mononucleosis, it is much more complicated to find out if it also prevents the development of cancer and multiple sclerosis because both pathologies they can manifest years after EBV infection.
The Epstein-Barr virus usually infects humans during childhood or adolescence and generally integrates into the genome of the cells it infects and reactivates throughout the life of the individual, so if the efficacy of this experimental vaccine If it is confirmed, the experts believe that the most convenient thing would be to administer the drug during childhood to prevent new infections and their long-term consequences.
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