If they get the shot before crossing the border, no need to worry, The Covid shot acts as an abortant in many cases. Isn’t it ironic that those who put damaging items in their body (drugs, alcohol, fast food/over eating, Covid shots) wind up self destroying? The body is a temple, given to you by God. You should care for it as such. For some it may take years before self destructing, and a lifetime of misery. You should respect yourself and your body.