Coronavirus truthers have a new boogeyman.

A far-right Facebook group that spans the U.K. and the U.S. recently erupted in alarm when a user posted, “There are people donating blood after being shot up with the covid crap. This terrifies me.” A wave of comments followed, all reflecting various degrees of deluded, conspiratorial thinking about shots that we know to be safe and effective.

“Isn’t there a rule not to??” one intoned. “Are people that stupid to donate blood after getting a shot?”