A QAnon video which takes Nobel Prize winner Luc Montagnier's suspect claims about covid vaccination and multiplies them beyond recognition states that mass vaccination will lead to mass ADE, and that all vaccinated individuals will die in 2 years. Ignoring the hysteria of this propaganda piece, I am interested to know more about when ADE is an actual risk.
This paper reviews ADE in the context of SARS-CoV-2 and claims that it appears to be a non-issue, for the most part. However, I would like experts to comment on my layman's understanding of the issue:
ADE can occur if a virus encounters 1) non-neutralizing antibodies, 2) neutralizing antibodies at a very low concentration, 3) antibodies which help the virus form complexes that plug up the respiratory system. Since vaccines generally don't contain antibodies themselves, whatever antibodies occur in a patient are the ones produced by the patient themselves. Therefore, if a patient produces non-neutralizing antibodies in response to a vaccine, then they may have produced the same antibodies in response to infection.
The exception mentioned in the paper is when an inactivated virus is presented and the body responds to a portion which results in non-neutralizing antibodies. Even so, I don't see why this couldn't happen in the natural infection route as well. The covid vaccines seem to have an even lower risk of ADE, because they only produce the spike protein, which seems to result in strongly neutralizing antibodies.
It seems to me that the greatest risk for ADE would be from monoclonal antibody (or convalescent plasma) therapy where the antibodies are not well-matched to the strain of infection, thereby having a higher risk of being non-neutralizing. It seems that this risk can be mitigated by sequencing the infection to ensure it is a known match for the antibodies.
