Near the end of January, the CIA announced it was leaning toward the lab leak theory as the best explanation for the origin of COVID.

"CIA assesses with low confidence that a research-related origin of the COVID-19 pandemic is more likely than a natural origin based on the available body of reporting. CIA continues to assess that both research-related and natural origin scenarios of the COVID-19 pandemic remain plausible," a spokesperson for the agency said in a statement, noting they "will continue to evaluate any available credible new intelligence reporting or open-source information that could change CIA's assessment."

Reports at the time said this was not simply the result of John Ratcliffe taking over as CIA Director but that a review of COVID origins information had been ordered by the Biden administration before Biden left office. The CIA had previously not offered an opinion either way but both the FBI and Energy Department had also leaned toward the lab leak theory.

Last week, Vanity Fair published an article about why the FBI was the first agency to take that side of the argument. The person most responsible for that decision is microbiologist Jason Bannan who is now retired from the FBI and able to speak about what convinced him, albeit without revealing any of the classified information he's seen.

He retired in 2022, and he spoke to VF in his capacity as a concerned citizen, not as a representative of the bureau. A portion of the FBI’s analysis is based on classified materials, but over numerous months he shared exclusively with Vanity Fair some of the open-source information that played a strong role in the bureau’s assessment...

Vanity Fair can now report that FBI scientists closely scrutinized the research activities of a group of graduate students and researchers who worked under Shi Zhengli, the lead coronavirus scientist at the Wuhan Institute of Virology (WIV). For at least three years prior to the pandemic, those scientists performed risky research on a group of viruses that included one of the closest known relatives to SARS-CoV-2, which causes COVID-19. The FBI found that Shi’s researchers, in their publications, were not candid about the inventory of viruses in their possession and the true breadth of their work, which was conducted in labs with a low biosafety level. The intelligence community also determined that, in the autumn of 2019, three of Shi’s researchers fell ill with COVID-like symptoms.

We've known about the sick researchers for several years. And way back in 2021, Josh Rogin revealed that in addition to having COVID-like symptoms the three researchers also lost their sense of smell. That symptom isn't exclusive to COVID but it's one more piece of evidence that makes a lab leak seem plausible.

In a 2019 paper, Dr. Shi Z and her researchers published a paper including a chart listing three different groups of bat coronaviruses they had studied. But it turned out they had intentionally left out a 4th grouping that included viruses most similar to COVID-19.

The paper concluded that the virus had likely resulted from the recombination of bat coronaviruses from several southern China provinces, including Yunnan. It contained a circular diagram known as a phylogenetic tree, which charted the evolution of three groups of bat viruses that the researchers had analyzed.

Among the coauthors were two scientists who had studied under Shi, Yu Ping and Ben Hu.

The published study omitted a key part of what the WIV scientists had been researching. A few months later, in June 2019, Yu Ping completed her similarly titled master’s thesis, “Geographical Evolution of Bat SARS-Related Coronaviruses,” which documented the research that informed the earlier paper. She described analyzing “bat samples collected in 20 regions in China from 2011–2016 that were available in the laboratory.”

The thesis, though available to readers at the Chinese Academy of Sciences, was not published for a wider readership. It contained the same phylogenetic tree as the earlier paper, but this time with an important addition: a fourth group of viruses, identified as Lineage 4, hailing exclusively from Yunnan Province. One of the viruses was labeled Ra4991. The thesis also notes that more than 2,800 samples came from Yunnan Province, with almost a third of them testing positive for SARS-like coronaviruses.

Why was lineage 4 left out of the 2019 paper? Ra4991 may not sound familiar but after the pandemic had started Dr. Shi published a new paper about a virus called RaTG13 which had been found to be 96% similar to COVID-19. But it turned out RaTG13 was the same virus as Ra4991. She renamed it and didn't mention that her lab had been researching it and viruses like it for some time.

Yu Ping and Ben Hu are two of the three scientists who got ill with COVID-like symptoms. Even curiouser, both of them have denied having been sick at the time at all but the US has intelligence that shows they are lying. It really does begin to look like a coverup. And you can add to that the fact that China tested them when they were hospitalized but has never released data on what precisely they were sick with.

As Ed described here last December, Dr. Bannan was prepared to defend the FBI call that the lab leak seemed the most likely explanation back in 2021 when the Biden administration wanted to look into the topic, but no one ever asked him to make his case. It seemed the Biden administration wasn't interested in getting the full picture.

Dr. Bannan still believes both explanations are plausible so he doesn't consider this settled but he does think that, of the two explanations, the lab leak really does make more sense. Hopefully, we'll get to learn more about the classified information supporting his view at some point.