WASHINGTON — Senate health leader Bill Cassidy (R-La.) grilled a Trump nominee for a key pandemic preparedness role over past comments in which he questioned vaccines, in a heated Senate confirmation hearing on Wednesday.

“Why would you repeat those damn lies? Because that destroys trust,” Cassidy said at one point to the nominee, Sean Kaufman, rapping his hand on the dais.

The senator was referring to a now-deleted LinkedIn post, first reported by STAT, in which Kaufman raised points commonly used by people who are skeptical of vaccines. Among other claims, Kaufman’s post made the case that the hepatitis B vaccine dose given at birth may be linked to an increase in autism cases, a widely-disproven claim.

The dramatic exchange comes after STAT reported last week that Kaufman, nominated to be Assistant Secretary for Preparedness and Response, had made a number of public statements questioning the safety of vaccines, including messenger RNA vaccines and the hepatitis B vaccine given to infants at birth. Cassidy referenced the story in his opening remarks at the hearing.

He also pointed to a video from four years ago, when Kaufman was running for his local school board, in which he said he hates the Centers for Disease Control and Prevention. If confirmed, Kaufman would work closely with the CDC in a public health crisis.