It's not, zoonotic transmission has happened many times, lab leak is the extraordinary claim requiring extraordinary evidence
It's not, zoonotic transmission has happened many times, lab leak is the extraordinary claim requiring extraordinary evidence
https://muse.jhu.edu/article/936217
So how many people have to die before this is no longer an extraordinary claim? Bhopal managed to change chemical manufacturing standards with "only" thousands or tens of thousands of deaths; but the 1977 flu is somehow completely forgotten.
Perhaps the death toll is so high that people simply can't believe it? YouTube's fact-checkers recently removed an unambiguously factual description of the 1977 pandemic, ignoring appeals well-referenced into the peer-reviewed literature with no stated justification.
https://www.spectator.co.uk/article/how-i-fell-foul-of-youtu...
So are you really saying p ~ 1/12 is an "extraordinary claim"? Is a 6'1" American man "extraordinarily tall"? There's unfortunately no standard map between English phrases and numerical probabilities, but I think most people would understand a much lower probability. If you really want to define it that way, then "extraordinary evidence" is likewise diluted to the point that the circumstantial case (emergence in Wuhan, DEFUSE) brings research origin easily into contention.
Yes, I think it is extraordinary to extrapolate one event in 1977 to a "once every fifty years" rate
I hope you're not going to count every natural spillover since prehistory in the denominator. The technology to culture and freeze an influenza virus didn't exist before ~1930, and the technology to genetically enhance a sarbecovirus didn't exist before ~2010. The absence of pandemics with such origin before that means nothing. No one had ever suffered a cancer induced by an X-ray tube before 1904; but that doesn't mean the risk wasn't there, and Edison's assistant still died horribly.
Can you explain why 2010 would be a reasonable start cutoff? That doesn't make any sense to me, since it excludes most of the time that a research-origin flu pandemic was possible. We obviously haven't had a research-origin novel sarbecovirus pandemic before maybe SARS-CoV-2; but when new technological developments occur, the most similar old technologies are our best model. Nobody had ever died in a plane crash before the Wright brothers, but anyone familiar with unpowered gliders could predict the risk.
Regardless of the source, it was dangerous but could have been better mitigated if it was taken seriously as a threat (not just a "common cold").