Dealing with COVID-19 Vaccine Related Antibody-Dependent Enhancement: A Mini Review

Author(s): Alexis Lacout, Jean-François Lesgards, Valère Lounnas, Xavier Azalbert, Christian Perronne, Martin Zizi

Antibody-dependent enhancement is an antibody-mediated increase of infection which is a paradoxical reaction of the immune system during viral infection, when generally non-neutralizing antibodies facilitate and exacerbate infection. The ADE phenomenon is well known in veterinary medicine. It is contraindicated to vaccinate sick animals with the Rotavec® vaccine (designed against a bovine coronavirus and a rotavirus). In humans, during SARS-CoV-1 infections, the S-protein epitope was shown to produce both neutralizing and ADE antibodies. Newly-infected patients were not considered vaccinated until 15 days after the second dose of vaccine. In these patients (considered unvaccinated (< 15 days)), the vaccine could be able to induce an increase in antibody levels, initially neutralizing at low concentration and/or facilitating. Indeed, the facilitating antibodies which appear two to three weeks after one dose of vaccine would therefore be present at the time of the second dose. In relation to these mechanisms, the vaccine could therefore facilitate contamination and induce severe forms in patients who had been vaccinated but were wrongly considered unvaccinated.