Aren’t there different levels and severities of Antibody Dependent Enhancement?
Sure, but the hallmark of ADE - the foundational concept of it - is that antibodies from previous infection or vaccination assist the new infection and present as worsened outcomes. If the outcome is less severe (at a population level - not at an individual level) in those previously infected or vaccinated, it is definitely not ADE.
ADE is most commonly seen in Dengue virus infections. Because there are 5 different types of Dengue virus and the body has difficulty distinguishing between them, someone who was infected by one type of Dengue virus will produce the same antibodies even if infected by another type of Dengue virus. These antibodies are sub-optimal and don’t neutralize the virus. Instead, they actually assist it in infecting cells and doing damage to the immune system. This leads to much more severe outcomes and is why a secondary infection with a different Dengue virus serotype is often so much more dangerous than the original infection.
If you’re doing research on ADE, I would highly recommend looking specifically at Dengue virus. It’s a great example of how ADE works, it’s well studied, and there’s no bias or political agenda attached to it like you might find if you research ADE specific to COVID-19. There’s a lot of fake info floating around about COVID-19, but pretty much anything about Dengue is (probably) going to be reliable background on how this process works.