Pressure for several seconds on the skin. And it’s over. Faced with the Omicron outbreak and the risk of other variants of Covid-19 appearing, a group of WHO experts is calling on vaccine manufacturers to review their composition.
In Lausanne, Switzerland, the Cbetween university of general medicine and public medicine Unisanté is testing an anti-Covid vaccine in the form of patch. It takes up, more or less, the principle of BCG vaccination and its micro-needles. Less impressive than the syringe, but not necessarily less painful, breathes Radiana Ferrero, the first volunteer to receive the product: “It burns a little more. Afterwards, it’s quite tolerable“.
But the interest of the vaccine lies less in its mode of administration than in the cellular immunity that it is supposed to develop, when RNA vaccines focus on antibodies. VShe PepGNP-Covid19 vaccine, developed in England by Emergex Vaccines, “relies on T lymphocytes, responsible for cellular immunity, to eliminate cells infected by the virus and prevent it from replicating“, specifies the center in charge of the experimentation.
“RNA messenger vaccines generate antibody levels which are excellent, with very good protection against severe disease. But of course they are relatively dependent on mutations, like the Omicron ” details Professor Blaise Genton, who coordinates the clinical trial. “So, the interest of a vaccine like the one we have is a cocktail of peptides, which are small fragments of proteins: injecting them into the dermis gives a better response, so potentially can be a better protection.“.
Better immunity against variants and which would last longer, thanks to the production of memory cells capable of fighting an infection for several years: all this remains to be confirmed of course. If it proves to be effective, the vaccine will not be available anyway before 2025. But, even there, it could still be used in the fight against Covid-19. “This is precisely one of the interests: increasing the range, if you will. Because if you only have two vaccines that are effective, such as Pfizer and Moderna for example, we are still at the mercy of shortages of components “.
“It’s always better to have a wider spectrum of vaccine possibilities.”Blaise Genton
The patch vaccine could indeed help reduce vaccine inequality. While the UN estimates that at the current rate of deliveries, Africa will not be able to vaccinate 70% of its population before the summer of 2024.
Covid-19: How does the vaccine in the form of a patch currently being tested in Switzerland work? Report in Lausanne by Jérémie Lanche