"Original antigenic sin" is the concept that once your immune system learns a particular pathogen, it tends to stick with that original immunity when faced with a new variant, which can potentially result in a failed or weakened immune reaction if the new variant is different enough to evade the antibodies. The takeaway is that a new vaccine-resistant COVID variant could end up being more harmful to the vaxxed than to the unvaxxed, because the vaxxed have been locked by the vaccine into a failed response that won't update because the body thinks it's still close enough.
By December 2021, the negative efficacy signal was already clearly present in the data so that doesn't mean you are particularly clever. Various people have been warning about the possibility of vaccine-enhanced immunity since these injections first came out in 2020/early 2021.
I posted that this would happen last December: https://www.reddit.com/r/kotakuinaction2/comments/r9fq51/original_antigenic_sin_and_how_the_vaccine_might/
By December 2021, the negative efficacy signal was already clearly present in the data so that doesn't mean you are particularly clever. Various people have been warning about the possibility of vaccine-enhanced immunity since these injections first came out in 2020/early 2021.