An adversary that develops a virus (e.g. another modified/mutated bat virus, for example) that selectively targets ADE in people with the specific antibodies from vaccination, which are distinct from natural infection, could easily kill every single person who was vaccinated and not harm or only make mildly sick those who either had Covid-19 naturally or who were uninfected and unvaccinated.
Threlkeld added, Williams also had been vaccinated for COVID about a month ago and that testing found the two types of antibodies in his system - one type of antibody that results from a natural COVID infection, and a second type of antibody from the vaccine.