Two scientists, Dr. Jean-Marc Sabatier and Prof. Jacques Fantini*, explain why the third vaccine dose can have serious long-term side effects due to the “ADE” phenomenon (Antibody-dependent enhancement: facilitation of infection by antibodies). The benefit/risk ratio would be unfavorable. Explanations.
The immune response and variants of SARS-CoV-2
The immune response to SARS-CoV-2, whether natural or vaccine-induced, produces antibodies directed against the spike protein. In the case of mRNA vaccines, the only molecular target is the spike protein. In the case of natural infection with the virus, the immune response is directed against several viral proteins, including the spike protein. In all cases, the spike protein is therefore crucial. However, SARS-CoV-2 is an RNA virus that mutates a lot, and many mutations affect the spike protein, which disturbs its recognition by antibodies.
The original strain has become obsolete
In the case of the current mRNA vaccines (“Comirnaty” from Pfizer-BioNtech and “Spikevax” from Moderna), the spike protein produced in the vaccinee is that of the original 2019 (so-called “Wuhan”) virus strain. This strain of SARS-CoV-2 has become “obsolete” because it has not circulated for more than a year; it has been replaced by variants, including the Delta variant and its sub-variants, which are now in the majority worldwide. The loss of vaccine efficacy is thought to be due (at least in part) to the different structure of the spike proteins of the current variants compared to the original “Wuhan” virus strain.