To fight against the COVID-19 epidemic, vaccines limit the severe forms but do not block the spread of the virus. This is why several strategies are developed in parallel, in particular the blocking of the multiplication of the virus in the nose. The choice of this area is no coincidence since SARS-CoV-2 infection begins in the nasal cavity. It multiplies abundantly there, then it spreads in the nearby environment. But it can also spread to the lungs, where it causes the most severe pathologies. Blocking its multiplication in the nasal cavity would therefore make it possible to curb the infection early and potentially the dissemination of the virus. Researchers from the National Research Institute for Agriculture, Food and the Environment (Inrae), in collaboration with the National Veterinary School of Alfort-EnvA and the University of Paris-Saclay started from this observation to try to use proteins which prevent the fixation of the virus and limit its multiplication. They succeeded in doing so, as explained in their study published in the journal PLOS Pathogens.
This consortium of scientists has indeed developed antivirals based on biosynthetic proteins, the AlphaReps. AlphaReps are proteins, made by microorganisms, that researchers can model almost infinitely. They meet a specific need: to offer an alternative to antibodies, which are difficult to model in the laboratory. They do not present a biological risk, “ which makes it a promising biotechnology for research and the pharmaceutical industry. “, specifies the Inrae on this subject. In addition, they have the advantage of functioning in the image of antibodies: they are able to recognize the attachment protein of the virus, the Spike protein. The researchers specifically selected two AlphaReps proteins, named F9 and C2. And this for a simple reason, namely that they each recognize a different part of the Spike protein with a very strong affinity. As a reminder, SARS-CoV-2 attaches itself via its Spike protein to the ACE2 receptor, a protein present on the surface of the cells of the respiratory mucous membranes, to infect us.
Long Covid: at least 17 million Europeans affected according to WHO
The Spike protein is therefore the key that allows SARS-CoV-2 to enter our cells and is one of the targets of the immune system against infection, and that of current mRNA vaccines. It thus turns out that the combination of the two allows superior antiviral activity, including on the Delta and Omicron variants. In addition to their strong antiviral capacity, these AlphaReps are very stable and inexpensive to produce: two essential assets for their development. “ Promising results for the development of antivirals to reduce the pathology and spread of Covid-19. », concludes the scientific team. A discovery which is moreover welcome when the World Health Organization has just given this impressive figure: at least 17 million Europeans would have suffered from disorders due to a long Covid in 2020 and 2021. Its modeling also indicates an increase 307% of new long COVID cases between 2020 and 2021, driven by the rapid increase in confirmed cases from late 2020 and throughout 2021.
Modeling also suggests that women are twice as likely as men to be affected. Moreover, the risk increases significantly among severe COVID-19 cases requiring hospitalization, knowing that the WHO estimates that one in three women and one in five men would be likely to develop long COVID. “While we still have much to learn about long COVID, particularly how it presents in vaccinated versus unvaccinated populations and its impact on reinfections, these data underscore the urgent need for a further analysis, greater investment and greater solidarity with those who suffer from this disease.,” said Dr Hans Henri P. Kluge, WHO Regional Director for Europe. He adds: ” millions of people in our region, straddling Europe and Central Asia, are suffering from debilitating symptoms months after their initial infection with Covid-19. They can’t go on suffering in silence. »