Senator Rand Paul argues in an opinion piece that his ongoing investigation has uncovered evidence that scientists behind the influential "Proximal Origin of SARS-CoV-2" paper privately doubted the conclusions they publicly championed. The March 2020 paper was widely cited by fact-checkers and health officials to dismiss the COVID-19 lab-leak theory, and Paul contends newly released internal communications show its authors held far less certainty than they projected, undermining the credibility of the paper's role in shaping official and media consensus.

According to Paul, Slack messages show virologist Kristian Andersen privately estimated a 30% chance the virus originated in a laboratory, while Eddie Holmes put the odds at 20%, later revising this down to 10%. Andersen reportedly described "smoking(ish) guns" that left him "not comfortable" with the paper's public conclusions. Paul frames this as evidence of a deliberate cover-up that he says he is continuing to expose "layer by layer" through his investigation.