I don't know where to start

One of my co-workers is leaning toward getting the COVID vaccine, but wants to know about this magnetism rumor. I told him it was a lie, but he says he's seen videos. I told him how they faked up those videos (small objects often stick to the skin) and why (because they'd told other lies and wanted to support those), and he said he'd still like to know what's IN the vaccine. I said "What does it matter? I'm not a chemist, I can't tell you what these substances do." The CDC saying it's safe means very little to him, and I do get being leery of our governmental agencies telling us things are 'safe'. We have a long history in this country of gov't saying that and then years later finding out that they were lying through their teeth. But what else can I say? I can't disprove this claim because I can't even get a handle on where to start with something so outlandish. Any ideas?

This on a backdrop of one of our other coworkers being in the hospital with COVID. Still not in a coma, but on oxygen. And she's young. We've been so lucky so far, in my work group.