Adsorption of SARS CoV-2 Spike Proteins on Various Functionalized Surfaces Correlates with the Strong Infectivity of Delta and Omicron Variants

Abstract: The SARS CoV-2 virus emerged at the end of 2019 and rapidly developed several mutated variants, specifically the Delta and Omicron, which demonstrate higher infectivity and escalating infection cases worldwide. The dominant transmission pathway of this virus is via human-to-human contact and aerosols, but another possible route is through contact with surfaces contaminated with SARS-CoV-2, often exhibiting long-period survival. Here we compare the adsorption capacities of the S1 and S2 subunits of the spike (S) protein from the original variant to that of the S1 subunit from the Delta and Omicron variants. The results clearly show a significant difference in adsorption capacity between the different variants, as well as between the S1 and S2 subunits. Overall, our study demonstrates that while the Omicron variant is able to adsorb much more successfully than the Delta, both variants show enhanced adsorption capacity than the original strain. We also examined the influence of pH conditions on the adsorption ability of the S1 subunit and found that adsorption was strongest at pH 7.4, which is the physiological pH. The main conclusion of this study is that there is a strong correlation between the adsorption capacity and the infectivity of the various SARS CoV-2 variants.