>But does it take years for the effect to show up after the alpha gal leaves your system?

For this specific change, no. But the point is that there is ample chance for mRNA to induce semipermanent and/or permanent changes and there's no guarantee that they'll be detected early, especially when the vast majority of clinicians aren't even looking for them.

If these vaccines do indeed, say, increase long term risk of cancer or heart problems, it will likely take years or even decades to detect especially when there is a rigid, top down enforced taboo around questioning the safety/efficacy of the vaccine. Yet another reason that censorship like this is dangerous.

Researchers also get some of their ideas through free exchange on social media. Especially when the academic establishment develops a rigid orthodoxy around a topic; when all of the institutions align behind a single preemptive conclusion and then collude to suppress even rational, science based dissent across all platforms, your society stumbles down the false path of one sided research.