#Covid-19 : le nouveau #vaccin de Pfizer et BioNTech bientôt approuvé aux États-Unis [et peut-être en Europe] sans essais cliniques sur l’homme ?
▻https://www.ladepeche.fr/2022/08/23/covid-19-le-nouveau-vaccin-de-pfizer-et-biontech-bientot-approuve-aux-etat
Mais, comme pour celui de la grippe, préalablement (et uniquement) testé chez la souris
The imminent #BA.5 vaccine booster - by Eric Topol
▻https://erictopol.substack.com/p/the-imminent-ba5-vaccine-booster
But there’s a concern that it’s not so easy to extrapolate mouse to human for SARS-CoV-2, a virus that’s quite different than influenza. A substantial proportion of people have had 3 or 4 shots of the original vaccine, so there’s the potential for imprinting—that is a preferential revving up of the immune response to what a person was originally exposed to, that is the version of SARS-CoV-2 (also known as original antigenic sin, a poor term since it’s not really a sin, it’s our immune system at work). That concept was just nicely reviewed with an explanatory graphic below.
So we don’t yet know the role of potential imprinting in people receiving the BA.5 booster. Moreover, both Pfizer and Moderna shots are bivalent, whereas the monovalent would be expected to be better, not further inducing an immune response to the obsolete ancestral strain, and with better data in the mouse model (if we’re really embracing data from mice). It’s unclear why a BA.5 monovalent vaccine isn’t going forward at this juncture.
