While the WHO calls for more effective and more universal vaccines against Covid-19, will the solution come from France? The National Research Institute for
agriculture, food and the environment (Inrae) and the University of Tours have been working for months on an effective vaccine against all variants, in the form of a nasal spray.
“At the level of the nose, the vibrating cilia and the mucus protect against particles which enter, but suddenly they also protect against the vaccine, describes Isabelle Dimier-Poisson, immunology specialist at the University of Tours and project manager. To circumvent this problem, we use a vector derived from starch, which is very adhesive. » In other words, the viral proteins should “stick” in the nasal cavities to provoke the immune response there.
→ REREAD. Covid-19: a nasal spray vaccine under study
The product works by pulverizing the coronavirus spike protein “but also other proteins of the virus less subject to mutation, explains Isabelle Dimier-Poisson. This allows it to induce protection against any variant.» The first tests, for the moment only on mice and hamsters, show efficacy against the starting strains and against the Delta variant, with an undetectable viral load. Other analyzes are in progress against Omicron, but the specialists are confident.
An effective vaccine against infection
The advantage of a vaccine in the form of a nasal spray is to erect a barrier as soon as the virus enters the body. Such a product would thus make it possible to protect against infection, in addition to avoiding damage to the lungs and therefore serious forms. What really curb the epidemic and limit the emergence of new variants. Be careful, however, because for the moment the team has not published any peer-reviewed scientific results.
Thanks to its format, this vaccine would make vaccination more accessible for those who cannot stand injections. In France, it could be used during possible winter recall campaigns. The team has also contacted the international initiative Covax for an application in countries where vaccination coverage is low. This anti-Covid vaccine would be sprayed twice with a three-week delay between each inhalation.
An unknown duration of protection
The big unknown remains the duration of protection. The researchers behind the project hope that it will last several months, but impossible to be sure for the moment. The team is continuing the work, in particular on the volume of product to be deposited and the type of spray to be used. Clinical trials in humans are expected to start in the fall of 2022, with the product on the market at the end of 2023 at best. Around the world, half a dozen nasal spray vaccines are currently in development phase.