Coronapod: COVID's origins and the 'lab leak' theory

Benjamin Thompson

Welcome to Coronapod.

Noah Baker

In this show, we’re going to bring you Nature’s take on the latest COVID-19 developments.

Benjamin Thompson

And we’ll be speaking to experts around the world about research during the pandemic.

Amy Maxmen

We’re entering a new era now. We have new COVID strategies, there’s some new unknowns and we’ve got a vaccine.

Benjamin Thompson

Hi, listeners. Benjamin here with this week’s edition of Coronapod. I am in the South London basement once more, but I’m joined on the line by Noah Baker and Amy Maxmen. Hello to you both.

Amy Maxmen

Hi.

Noah Baker

Hi, Ben. Hi, Amy.

Benjamin Thompson

Today on the show, we are going to be looking at one of the big questions that researchers have been grappling with, well, since the very beginning of the pandemic, I guess, and that is where did the SARS-CoV-2 virus come from? Now, we’re expecting some news from the WHO – we don’t quite know when that’s going to be – but it will be the final reports from the WHO team who went to China a few weeks back to try and get a bit of a handle on the answer to this question and, Amy, this is something that you wrote about at the time.

Amy Maxmen

Yeah, so they had a press briefing on 9 February about their investigation and to be clear, WHO sort of organised the trip. This is why we need a WHO. They did sort of the logistics, they put it together, but the team wasn’t all WHO people. There were some WHO scientists but it was 17 researchers who were from China and 17 international scientists. So, they spent two weeks in China, mainly in Wuhan, figuring out what they could about how this all started.

Noah Baker

I’m really keen to know one of the big questions which is why do we care at this point, right? This happened a long time ago. It was horrible. It happened. Why do we need to know? Is it just digging up old ground at this point?

Amy Maxmen

Well, I mean, I guess the idea is we want to know where scary new infections emerge from. So, the idea is that if we can figure out how this began, maybe we can try and prevent it the next time, and so I think whenever there is a new outbreak of kind of an emerging disease, there is really a race to figure out how it happened because you want it to not happen again.

Noah Baker

Okay, in which case, what have they found? What is the sort of outcome of this long search? Because we’ve talked a lot about the various different origin hypotheses and ideas. We know that it’s likely that this originally came from a bat, but we weren’t sure whether or not there was in intermediate host. There was a lot of talk at the beginning of the pandemic about this particular wet market, this live animal market. Any news on that? Is that still the prime suspect? Where have the WHO and that team of scientists got to in their search?

Amy Maxmen

Yeah, so this was very much like an investigation for what was the origin, but I want to underscore one thing first. This is two weeks which is really nothing. None of the scientists I spoke to for the story about this were like completely surprised that we don’t have the definitive story of where this came from because it was two weeks. Still, it’s a good start. So, you set up collaborations, you figure out logistics, maybe you don’t’ have to meet every single person in every single lab the next time around. So, anyways, this is kind of what they did. So, they went to Wuhan, they confirmed this idea that the first case that we know about was on 8 December 2019. That’s when an office worker in Wuhan complained of having these COVID-like symptoms. So, that’s kind of as far back as we get, but they tried to trace it back even earlier. So, they did a lot of digging. They reviewed a lot of health records from Wuhan and the surrounding area from the second half of 2019, and they identified in these records around 100 people who had symptoms that looked like symptoms of COVID-19. They went and they actually found 67 of these people, they tested them for SARS-CoV-2 antibodies but they didn’t find any antibodies in these people. So, they also went to hospitals and they found 4,500 patient samples and they tested all of those samples for the SARS-CoV-2 virus and again, they didn’t come up with anything. So, they didn’t find evidence that this was at least widespread before December 2019. And then there was that wet market you mentioned and towards the beginning, a lot of cases of COVID where traced back to this wet market in Wuhan. But we’re still not sure about that hypothesis because it turned out that a lot of other people with COVID hadn’t gone to that wet market. But nonetheless, they went back and they identified ten stalls that sold wildlife that are live, and those were either wild or farmed animals, things like rabbits and badgers and things that we now know are susceptible to getting SARS-CoV-2. So, they identified these stalls but they didn’t really go deeper than that. I think that’s a time constraint issue. And previously, researchers in China have tested around 30,000 wild, farmed and domestic animals, but they still hadn’t found any evidence of SARS-CoV-2 infection except for some cats, but that was in like March 2020 so they could have gotten it post this pandemic.

Noah Baker

So, it’s looking like perhaps the market may not be the front runner, which is something we’ve been thinking for some time, but there is still a hypothesis that this could have come from meat or come from animals, specifically frozen meat. Can you tell us more about that?

Amy Maxmen

Yes, so that’s something else that the team explored. And this hypothesis that SARS-CoV-2 was in some frozen food that people then ate and that’s how it started, this comes from a few different studies. So, there’s a preprint on bioRxiv that appeared in August, and it found that SARS-CoV-2 can remain infectious on the surface of frozen or refrigerated meat for more than three weeks. There’s another line of evidence which was there was an outbreak in Beijing that just seemed to sort of pop up out of nowhere, and the investigators of that outbreak found some viral particles on cold-stored salmon at a market stall in Beijing, so that was another thought about maybe where this outbreak came from. And what the WHO did is they went through a lot of that evidence, but they came up with nothing there. They didn’t find much more as far as this being carried on frozen salmon. So, I would say among the scientists that I talked to, it’s not really holding a lot of water. That’s definitely not their leading hypothesis because there’s not a ton of support for it. Whereas, we can think about natural spill over, there’s a lot of evidence for that. One is we know that bats carry tons of coronaviruses, we know that there’s lots of other coronaviruses that are found in nature and that have spilled over like SARS and like MERS, so that’s why this idea that being a natural origin sort of makes sense when you think about the way that evolution works and the way that animals harbour coronaviruses.

Noah Baker

And you’ve said natural spill over several times there, but there’s one other kind of hypothesis, which was bandied around quite a lot at the beginning of the pandemic, it’s stemmed a series of conspiracy theories, which is that perhaps this virus was actually leaked from a lab either deliberately or accidentally. Now, we should add that the evidence suggests that that is not what happened, but it is something that the WHO has looked into.

Amy Maxmen

Yeah, for sure, and they need to because I think it’s quite popular, here in the US at least I can say for sure, not super popular among the scientific community, but it’s definitely something that people still think might have happened even though there’s not a lot of evidence for it. So, there’s this Wuhan Institute of Virology and it happens to be in Wuhan, so I think the main line of thinking here is like, well, that’s just too much of a coincidence. So, what the WHO did is they went to this Wuhan Institute of Virology and they had sort of extensive discussions and interview with everybody who works at the Wuhan Institute of Virology and they concluded it was unlikely that it was leaked from there and also that the scientists there didn’t know anything about this virus, they weren’t handling a virus that looked like this, and they didn’t know anything about it prior to December 2019, so there’s really nothing to support that idea.

Host: Benjamin Thompson

And yet it’s an idea that just won’t go away and it’s maybe not the first time, not the first disease outbreak, that the finger has been pointed at something like this either, is it, Amy?

Amy Maxmen

No, it’s not. There’s a couple of virologists who’ve really studied sort of the evolution of coronaviruses and they’ve put out a couple of papers. For example, in March, there was a paper by Kristian Andersen and Robert Garry from Tulane University and that really looked at the changes within the RNA or coronaviruses and sort of said this fits in perfectly within a family tree, so it doesn’t make sense that it was something that was just created. But they realised with that paper that people were not sold on the idea. And when I talked to Bob Garry, he’s sort of, I don’t know how to say it, he’s a bit pessimistic here because he feels like there’s really nothing that’s going to convince a certain set of people that it’s not a lab leak, and this comes from prior experience. He has a lab that I actually spent a lot of time in in eastern Sierra Leone that studies haemorrhagic fevers, and he set that lab up in this area because there’s a lot of Lassa fever here. That’s a disease that appears a lot like Ebola. It’s another viral haemorrhagic disease. So, he created this lab there and then there was an Ebola outbreak nearby, and immediately he was being accused of having created Ebola and leaked it out. So, he’s been at the centre of this before. He kind of said something that stuck with me a little bit. He was sort of like, ‘You build a fire station in a place where there’s a lot of fires, and this is kind of like there’s another big fire in that area and people turn to the fire station and say, well, kind of fishy that you’re there, right?’

Noah Baker

I have to say that when the pandemic really started to take hold and this lab leak hypothesis started gaining traction among particular groups of people, especially conspiracy theorists, Nature had a huge spike to one article that it had written in 2017, massive spike actually, which was about the opening of this lab in Wuhan, and the headline of the article was ‘Inside the Chinese lab poised to study the world’s most dangerous pathogens’, and you can see how people will put two and two together and they’ll think hang on, lab that studies most dangerous pathogens in the place where we’ve found that a pandemic is emerging from? People jump to that really quickly, and it’s a bit of a logical fallacy to do that because that’s not really how those things work. Just because those two things are coincidental doesn’t mean they are causal, but people do jump on that bandwagon. And I was so fascinated by this conversation that you had that I wondered if it might be interesting to do a bit of a Coronapod first and just listen to kind of a couple of minutes excerpt from that conversation.

Bob Garry

Well, people will get these preconceived notions, these prior hypotheses in their minds and then it’s hard to get them out, but it can be used against you. Your competitors can say, well, look, they have all this laboratory research going on, they have the virus in their freezers and so they must have just released it to get more funding or something like that, and I don’t think you’re ever going to convince people that the reason you’re there was because diseases like this were present before.

Amy Maxmen

You said your competitors, so you feel like scientists also fuel this idea?

Bob Garry

Yeah, it can happen. It sounds untoward and something that you wouldn’t do if you were a scientist, but it happens.

Amy Maxmen

So, in that case, I feel like there’s a motive, right? It’s like there’s competition there. But have you come to any thoughts about why this is such an appealing hypothesis out there for a lot of folks who are not scientists?

Bob Garry

I mean, in terms of the COVID-19 outbreak, there’s a lot of politics that are going on. And obviously I’m not a politician so I can approach it from a scientific point of view, but there’s a lot of that preconceived sort of bias. Some of the people that are doing a lot of these hypotheses just want to pin something that nefarious on the Chinese government. There’s a whole other class of people too that are opposed to doing research on animals and a lot of people that go out to look for new viruses in the wild obviously are going out and trapping bats and other species, and some people are just basically opposed to that. There’s another whole group of people that are opposed to genetic engineering of any kind and yet another group who are kind of opposed to doing research on viruses that we call gain-of-function research. Now, there’s a lot of confusion about that term. Most of the work in virology doesn’t involve trying to make the virus more pathogenic. That would be gain-of-function research, and there’s some legitimate reasons to do that, but there’s a vocal group of people that are just violently opposed to that so a new outbreak occurs, the gain-of-function critics come out and say maybe that was gain-of-function research that just got out of control.

Host: Benjamin Thompson

So, it seems like a fairly sort of broad group of people then, Amy, that maybe have subscribed to this theory and, I think, in a Coronapod many, many months ago now, we talked about, I think we called it the misinformation-disinformation pandemic, and how seemingly disparate groups would come together under an umbrella to all believe something that collectively you might not expect them to.

Amy Maxmen

Yeah, I thought Robert Garry’s different categories of people who do this is really interesting, and to me it speaks to sort of prior biases. If you’re someone who sort of thinks that scientists cause harm in the world through GMOs or animal testing or human testing then maybe it’s kind of appealing to have a hypothesis where somebody intentionally wants to cause harm through a lab leak. I should say, I very much believe we should investigate lab leaks because they do happen, so I don’t want to say this could never happen, that scientists would never make this mistake. Of course they make mistakes. But I could see how that hypothesis could be overwhelmingly appealing even without evidence for somebody that’s pretty sure that scientists usually do harm in the world.

Noah Baker

Absolutely, it’s the kind of confirmation bias problem that we’ve faced many times throughout this pandemic, and it stems from a position where peoples’ willingness to believe a theory is driven more by, I suppose, their political, moral views or their desire to believe it than it is for the actual evidence that this particular thing happened in the first place.

Amy Maxmen

Yeah.

Noah Baker

One thing that I was really fascinated by that Bob Garry was talking about is the idea that researchers could potentially get on this bandwagon, again and he kind of referenced the idea that maybe it would be in their interests for your lab to lose funding, I guess because they might be able to get more funding. I mean, did you speak any more with him about that?

Amy Maxmen

I didn’t. I was also really surprised. I didn’t hear more but you’re right, that would be a great story. What kind of reporter am I? That is the obvious follow-up question.

Noah Baker

So, the WHO and this group of scientists have looked into these allegations, have investigated these allegations of lab leaks and they haven’t found any evidence for that. And as well as that, there is also some scientific evidence to suggest that various of the versions of the lab leak hypothesis are also not necessarily going to be true.

Amy Maxmen

Yes, there was another paper that came out in Nature Communications on the same day as the WHO press conference on 9 February. That one also refutes one of the theories that the lab leak people would sort of use to refute studies looking at the evolution of coronavirus. They would say, ‘Oh, there’s this one change within the spike protein that no other coronaviruses have so that shows it couldn’t have been evolution and it has to have been lab-made,’ and this paper showed that there was a coronavirus that’s very similar to SARS-CoV-2 and it’s in horseshoe bats that were found in a cave in Thailand in June 2020, and that it was super similar and the spike protein is very similar to SARS-CoV-2. So, that’s just kind of another line of evidence saying this is something that could be naturally occurring. And I mean, something else that another scientist brought up when I was reporting this piece was maybe what would convince people is like this really perfect nail in the coffin, Agatha Christie ending where we know all of the parts of how SARS-CoV-2 started, but the truth is, we pretty much will never have that because that perfect scene like at the end of Contagion where we see Gwyneth Paltrow shaking the hand of the chef, we don’t actually ever see that in real life. Even the sort of story of how the West Africa Ebola outbreak started, where there’s a young boy who’s playing underneath a tree where bats roost, that’s very hypothetical. So, the truth is, if we’re looking for that perfect scene, we’re probably not going to find it. Everything is going to be sort of these studies that add more evidence into one category and a lack of evidence into another category.

Noah Baker

And it’s also worth mentioning that as we get more information and as investigations go on, it may get more complicated before it gets simpler. I mean, there have also been reports of SARS-CoV-2 RNA or certainly RNA that looks a lot like it being found in blood samples from European countries from before December. Now, that needs to be verified, but that could suggest that SARS-CoV-2 was actually being transmitted around the world quite some time before. But we don’t really know and these investigations need to continue for us to be able to find out those answers.

Host: Benjamin Thompson

Which brings us back round, I guess, to what I said at the start of the show. The WHO’s report on this trip is due out. What’s the value of them kind of saying, ‘Well, we don’t really know. We still think it’s this but we don’t know for definite.’ Is this not just going to add more grist to the mill for people to say, ‘Ah, but you would say that, wouldn’t you?’

Amy Maxmen

I think there’s going to be a set of people that are going to say that no matter what. But what I’ve read is it’s not like they went to Wuhan and did nothing. So, they’ve done a lot. The fact that they didn’t come up with evidence still tells you something. That’s sort of the process of science is often ruling out sort hypotheses. They did explore the idea that this was spreading widely in November and December in China and they didn’t come up with anything, so that sort of tells you something even though it’s a negative result. I think that’s the funny thing about science, like some of the most interesting results are negative results.

Noah Baker

And in the meantime, the kind of search for the origin origin, by which I mean the animal origin, the bats that this first came from, is also ongoing, which is a kind of slightly separate search to work out how the transmission into humans happened at some point, and so we’ve talked about that on Coronapod before, people digging up bats from freezers, trying to find coronaviruses that are very closely related to this one to see if they can get a better sense of how it could have evolved in their original bat hosts.

Benjamin Thompson

Well, let’s leave it there for this week’s show. Perhaps we’ll touch on the report when it comes out in a future episode. But for the time being, Amy and Noah, thank you so much for joining me.

Amy Maxmen

Thank you, always a pleasure.

Noah Baker

Thanks, Ben. Thanks, Amy.