Two million patients could have their lives changed. In France, four million people are affected by asthma and, in half of the cases, they suffer from allergic asthma. For these patients, attacks are triggered by the inhalation of allergens, most commonly house dust mites. In order to fight against allergic asthma, scientists from Inserm, CNRS and Toulouse III-Paul Sabatier University in the Infinity laboratory of the Institut Pasteur and the French company NEOVACS have developed a new vaccine. . The findings were published in the scientific journal Allergy.
In allergic asthma, exposure to house dust mites triggers an overproduction of antibodies called immunoglobulin E (IgE) and proteins called "type 2 cytokines" in the airways. "This phenomenon leads to a cascade of reactions resulting in hyper-responsiveness of the airways, overproduction of mucus and eosinophilia [an excessively high level of white blood cells called eosinophils in the airways]", details Inserm in a press release. If, currently, inhaled corticosteroids help to control asthma, they are not sufficient for a severe allergy. These patients are then treated with therapeutic monoclonal antibodies targeting IgE or the IL-4 and IL-13 pathways.
But these drugs are restrictive, and this discovery could benefit these severe allergies. Indeed, researchers have been working for several years to offer them other alternatives. To assess the effectiveness of this vaccine, it was tested in a house dust mite allergic asthma model in so-called "humanized" mice. That is, rodent genes have been replaced by human genes. "A vaccination against allergic asthma represents a hope for long-term treatment of this chronic disease, and, beyond that, a prospect of reducing allergy symptoms linked to other factors, since this vaccine targets molecules implicated in different allergies, "said Pierre Bruhns, head of the Antibody Unit in Therapy and Pathology at the Institut Pasteur, in the Inserm press release.
What are the results of this study? "Vaccination induced a strong antibody response, capable of neutralizing human IL-4 and IL-13 cytokines, without diminishing vaccine efficacy, up to more than three months after injection [time corresponding to duration total of this study] ”, details Inserm. The researchers also noticed a significant effect on asthma symptoms with a reduction in mucus production and airway hyperreactivity with the Kinoid® vaccine.
“This study provides proof of concept of the vaccine's efficacy in neutralizing human proteins that play a key role in allergic asthma. We are thus paving the way a little further for the organization of clinical trials. We are currently discussing with all the project partners to set up these studies in humans,” explains Laurent Reber, Inserm Infinity Research Director (Inserm/CNRS/Université Toulouse III-Paul Sabatier). Finally, this vaccine could also be of interest in the case of a food allergy or atopic dermatitis.
