There are currently four variants of concern (VOC) and four variants of interest (VOI) of SARS-CoV-2. These variants have in common increased transmission and partial resistance to vaccines and certain antibody-based treatments. While the pandemic is not slowing down, others will emerge in the future.
To deal with this problem, the High Authority of Health recommends the injection of a third vaccine dose for people 65 years and over, and those who have a significant risk of declaring a severe form of Covid-19. The third dose should be spaced at least six months after the second. But this is not the only strategy being investigated.
Two publications, published a few days apart in Immunity, each present a highly neutralizing antibody effective against SARS-CoV-2 variants.
Target a conserved region of protein S
The first monoclonal antibody, called SARS2-38, was isolated by a team from the Washington School of Medicine. It is the only one, among the 43 isolated from the serum of mice immunized with the receptor binding domain (RBD) of the coronavirus, to keep its neutralizing activity for all variants. Indeed, SARS2-38 binds with great affinity to part of RBD, the region of the S protein in physical contact with the ACE2 receptor, which varies very little between the variants. Thus, although many variants have one or more mutations in RBD, the efficacy of SARS2-38 is not affected.
Scientists have shown that SARS2-38 can neutralize all variants tested in vitro, namely the major variants Alpha, Beta, Delta and Gamma and other minor variants such as the Iota and Kappa variants. From…
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