possible, but in fact unlikely. Whether immunity comes from vaccines or prior infection (remember, people can become infected more than once, so it is also not "preventing transmission"), the evolutionary pressure to mutate around existing defenses is present. So, vaccines would have to make that so much worse that it'd overcome orders of magnitude fewer opportunities. Sure, zero is better, but it is not completely necessary.

In observation with covid, the last two major variants have come in places where vaccination rates are low.

In history, I don't think you could find a vaccine where this effect has meaningfully occurred.

It just doesn't add up which is a pretty great explanation for why he's essentially the lone scientist making that claim.