Herd Immunity is just another way of saying that vaccines are only marginally effective. If they work, you're protected. If they hardly work, then you might in theory gain something by vaccinating everyone.

Unfortunately though, in many cases they're worse than no vaccine. Not only do they not work, they cause the disease they're supposed to prevent, weaken the immune system overall, and cause side effects.

Anyway I'm not a farm animal. We're not a herd. If you are going to eat a cow, you don't care if it gets auto-immune disease and autism. You're going to inject it with whatever poison garbage you think will reduce the chance of disease by a small margin.

Quarantines are more effective. Send the diseased 3rd world invaders back