If Jon Stewart has made the lab-leak hypothesis cool, former CDC director Robert Redfield is practically avant garde. More than two months ago, Redfield went on CNN to discuss the merits of that explanation of the origin of COVID-19. Days later, WHO chief Tedros Ghebreyesus contradicted his own agency’s analysis and demanded more investigation into any possible role played by the Wuhan Institute of Virology.

Redfield appeared on Fox News today to emphasize why he believes a lab leak is a better explanation than zoonotic transfer, although unfortunately he never gets around to mentioning his celebrity protege:

“I said before that I didn’t think it was biologically plausible that COVID-19 went from a bat to some unknown animal into man and now had become one of the most infectious viruses,” Redfield said during an interview with Fox News.

“That’s not consistent with how other coronaviruses have come into the human species. And, it does suggest that there’s an alternative hypothesis that it went from a bat virus, got into a laboratory, where in the laboratory, it was taught, educated, it evolved, so that it became a virus that could efficiently transmit human to human,” he added. …

Redfield expressed disappointment in what he described as a “lack of openness” in the scientific community to “pursue both hypotheses.”

“I’m just giving my best opinion as a virologist, and I don’t think it’s plausible that this virus went from a bat to an animal — we still don’t know that animal — and then went into humans and immediately had learned how to be human-to-human transmissible to the point of now causing one of the greatest pandemics we’ve had in the history of the world,” Redfield told Fox News.

Redfield has been consistent on these points, and careful as well. Note how he uses the proper word — hypothesis —rather than “theory.” As I noted in the earlier post, the scientific use of the word “theory” reflects an idea with substantial evidentiary support. Hypothesis refers to explanations that attempt to explain an unknown that lack convincing evidence. Redfield is still approaching this question with scientific caution; he allows that the zoonotic-transfer hypothesis is also valid, even if he thinks that it’s less convincing at this point.

That should build up Redfield’s credibility among his fellow scientists. At least, it should with those who didn’t send him death threats in March for daring to speak about a valid hypothesis. Hence his lament about the lack of “openness,” which Redfield experienced in a highly acute manner.

Stewart’s Overton-window shift will hopefully have other scientists discussing and investigating all of the possibilities, and not just the politically-correct one. I’d be interested in a follow-up on Redfield’s other point about the US going down the wrong path in assuming COVID-19 was similar to SARS. It is similar in construction, but not in performance, which is one reason why Redfield believes an artificial origin makes more sense. But why did we assume it would act like SARS? Was that our scientists making best-guess estimates in the absence of data, or did they take direction on that point from others? WHO, perhaps, or China? That will be an interesting question to pursue.