Very easily, actually. But it wouldn’t matter.
No, it’s an informal fallacy. Further, your dearth of knowledge about biology is the only reason you think it’s possible that the vaccines may spontaneously cause new, unforeseen medical problems.
"Spontaneously cause new, unforeseen medical problems"??? I don't recall ever saying that, though the potential for unforeseen twists, turns and issues certainly always exist with new technologies of any significant complexity. It's quite sad that you and others don't realize basic things like this, yet you claim to be a scientist, (God help us....).