And just in From Japan....
https://www.biorxiv....7114v1.full.pdf
Not quite proof of ADE, but certainly concerning.....
And it certainly indicates that booster with the original strain could possibly have dire consequences...
But despite all the torpedoes in the water, Fauci and crew going full speed ahead towards them....
Boost at your own risk....
The SARS-CoV-2 Delta variant is poised to acquire complete resistance to wild-type spike vaccines
The Delta variant has multiple mutations in the NTD: T19R, G142D, E156G, F157del and R158del. All anti-NTD neutralizing antibodies failed to recognize the Delta spike, indicating that the Delta variant is completely resistant to anti-NTD neutralizing antibodies elicited by wild-type spike protein, which is the antigenic component of widely used mRNA vaccines.
In contrast, most anti-NTD enhancing antibodies recognized Delta spike at the same level as wild-type spike, and some anti-NTD enhancing antibodies exhibited increased infectivity enhancement by Delta pseudovirus compared to wild-type pseudovirus.
These data indicated that mutations in the NTD are involved in the escape of SARS-CoV-2 from neutralizing antibodies. It is likely that the mutations in the NTD that abrogate neutralizing antibody binding while retaining enhancing antibody binding are beneficial to the virus.
A third round of booster immunization with the SARS-CoV-2 vaccine is currently under consideration. Our data suggest that repeated immunization with the wild-type spike may not be effective in controlling the newly emerging Delta variants. We demonstrated that immunization by Delta spike induces antibodies that neutralize not only the Delta variant but also wild-type and the Delta 4+ variant without enhancing the infectivity.
However, epitopes of the enhancing antibodies, not neutralizing antibodies, are well conserved in most SARS-CoV-2 variants, including the Delta variant. Therefore, additional immunization of the spike protein derived from SARS-CoV-2 variants may boost enhancing antibodies more than the neutralizing antibodies in individuals who were previously infected with wild-type SARS-CoV-2 or immunized with vaccines composed of wild-type spike protein.