A diary played an unusual role in a contentious Senate hearing Wednesday -- musings from Anthony Fauci, MD, a scientist who became a leading voice in the U.S. response to the COVID-19 pandemic.

Sen. Rand Paul, MD (R-Ky.), for years has accused Fauci, the longtime top infectious disease official at the NIH, of lying about the origins of the coronavirus. In previous hearings, the now-retired Fauci denied the accusation, calling it "preposterous." On Wednesday, he invoked the Fifth Amendment in declining to answer more questions.

But Paul drew public attention to the latest proceeding by releasing more than 1,000 pages of a long-running diary that Fauci kept – entries that Health Secretary Robert F. Kennedy Jr. told Fox News his agency extracted from government computers and provided to the GOP-led committee.

Paul drew on selected excerpts to argue that Fauci's "private record tells a different story" than what he told the country.

Some of the entries already were reflected in Fauci's 2024 memoir and in interviews at the time -- including the uncertainty that he and other scientists faced as they tried to understand a never-before-seen virus and how best to fight it. Here are some takeaways from the diaries, including quotes that have been edited to remove typos: