William Brangham:
Judy, trying to understand the origins of COVID has been a complex and politically fraught undertaking for nearly three years.
The Chinese government has been accused of obstructing the full investigation. But this new research attempts to get the clearest picture to date.
And I’m joined by one of its authors. Angela Rasmussen is a virologist at the Vaccines and Infectious Diseases Organization at the University of Saskatchewan.
Dr. Rasmussen, Great to have you back on “NewsHour”.
So, — at the start of the pandemic, there was a lot of focus on this live animal market. And you and several of your colleagues, including Michael Vorobey, have found some very strong evidence in your paper that indicates this was the epicenter of the outbreak.
What is that proof?
Angela Rasmussen, University of Saskatchewan: We plotted all the initial cases from December of 2019 on a map of Wuhan, whether or not they were linked to the Huanan market, and there were many of them.
It was identified as a location that was important in the investigation of the outbreak. We found that, whether or not those cases were market-linked, whether they were in the market or not, they actually piled up around the market and formed almost a circle around the market, where the market was dead center.
Another piece of evidence is that we know that live animals, including some susceptible to SARS-coronavirus-2 infection, were being sold at the Huanan market, which included November and December 2019. And, in addition, there were environmental samples. Collected from the site of the market where these animals were sold were positive for SARS-Coronavirus-2.
This really strongly indicates that those samples, those environmental samples, must have come from animals. And on top of that, those specimens were often collected from items attached to the animal, such as cages, hair and feather removal devices, and carts.
And then, finally, there were actually two different genetic varieties, or variants, of SARS-coronavirus-2 that were on the market, Lineage A and Lineage B. Initially, we thought lineage B was spreading in the market, but we didn’t realize that lineage A was also there, until it was found in a sample of the environment.
This suggests that there really should have been two separate introductions to the market. And the only thing that makes it clear is that two people are freely entering the market and getting infected with lineage B and lineage A in a span of about a week.
