Infection-enhancing anti-SARS-CoV-2 antibodies recognize both the original Wuhan/D614G strain and Delta variants. A potential risk for mass vaccination

Yahi et al.: so it is the binding to the virus by non-neutralizing Abs that do not eliminate the virus but increases infectiousness…it enhances the infection capability and explains why the vaccinated are getting infected; the non-neutralizing Abs bind to the virus in the upper respiratory tract and drive infection yet binds to the lower respiratory tract and prevents severe disease (transfection from infected to non-infected cells). This study shows original antigenic sin and ADE.

“our data suggest that the balance between neutralizing and facilitating antibodies in vaccinated individuals is in favor of neutralization for the original Wuhan/D614G strain. However, in the case of the Delta variant, neutralizing antibodies have a decreased affinity for the spike protein, whereas facilitating antibodies display a strikingly increased affinity. Thus, ADE may be a concern for people receiving vaccines based on the original Wuhan strain spike sequence (either mRNA or viral vectors).”

Source: https://pubmed.ncbi.nlm.nih.gov/34384810/