Antibody Dependant Enhancement

On March 18, 2020, when Moderna was ready to test its vaccine in the first phase (phase I) of the clinical trials, an article was be published in the journal Nature entitled: “Coronavirus Vaccines: Five Important Questions When Trials Begin: Will It Be Safe? ” .

The article argues that when vaccines are given to a large number of healthy people, the most important issue related to the concept of safety is a phenomenon called Antibody Dependent Enhancement (ADE).

In studies of an experimental SARS vaccine reported in 2004, vaccinated ferrets (experimental animals) developed harmful inflammation in the liver after being infected with the virus. Their conclusion was that those vaccines induce potent neutralizing and protective responses in immunized animals but may induce antibodies that enhance infection by early human SARS-CoV and animal SARS-CoV–like viruses .                           

On July 13, 2020, a more comprehensive article was published in Nature in which the authors write:

“Antibody-dependent enhancement (ADE) of disease course is a general concern because the mechanisms underlying antibody protection against viruses have a theoretical potential to amplify the infection or trigger harmful immunopathology after vaccination.”

On September 13, 2020, a third article was published in Nature Microbiology entitled: Antibody Dependent Enhancement and SARS-CoV-2 Vaccines and Therapies.

After a comprehensive review of the issue, the authors conclude with the following statement –
“ADE has been observed in SARS, MERS and other human respiratory viral infections, indicating a real risk of ADE for SARS-CoV-2 vaccines and antibody-based interventions. However, clinical data have not yet been able to fully establish a role for ADE in human COVID-19 pathology »

The authors go on to state that:
“In the future, it will be crucial to evaluate animal and clinical data sets for signs of ADE, and to balance ADE-related safety risk against intervention effects if clinical ADE is observed. Ongoing clinical studies in animals and humans will provide important insights into the mechanisms of ADE in COVID-19. »

As far as we know, no animal studies have been performed with Pfizer, Moderna, AstraZenca or the other vaccines that have included challenge studies. The Phase III clinical trials conducted with «Warp Speed» have not been able to provide a basis for about the possible risks of developing ADE.

So – over time – if the vaccinated are exposed to SARS-Cov2 or possible other corona viruses, what is the probability that there will be an increased risk in vaccinated groups for serious side effects and deaths that can occur after 3 months, 6 months or even one year after receiving the vaccine? As the clinical trials were opened to giving vaccines to the control group they no longer have the ability to be able to document neither the effectiveness nor the the possible longer term adverse clinical outcome of these biologicals.

According to a recent article in the Journal of Infection “Current Covid-19 vaccines (either mRNA or viral vectors) are based on the original Wuhan spike sequence. In as much as neutralizing antibodies overwhelm facilitating antibodies, ADE is not a concern. However, the emergence of SARS-CoV-2 variants may tip the scales in favor of infection enhancement. Our structural and modeling data suggest that it might be indeed the case for Delta variants”.