Dr. Anthony Fauci, who led the nation's infectious disease efforts during the pandemic, invoked the Fifth Amendment on Wednesday and declined to answer questions from a Senate committee investigating the origins of COVID-19.Why it matters: Fauci said Sen. Rand Paul (R-Ky.), the head of the Senate homeland security committee, was trying to get him to say something that could put him in legal jeopardy.Former President Biden gave Fauci a preemptive pardon before leaving office, but Fauci argues he could be in trouble if he makes any statements that could open new lines of investigation for the committee.What he's saying: Paul has an "unhinged obsession with me," and his motive for the hearing is to "get me to say something — anything — that could vindicate his repeated public pledges that I end up, in his words, quote, behind bars unquote," Fauci said."Although it pains me to do so … under the advice of my attorneys, I will invoke my right under the Fifth Amendment of the Constitution to refrain from answering your questions," Fauci said.The other side: "There will be repercussions to your refusal to testify today," Paul told Fauci.This is breaking news. Check back for updates.