What next in hunting for Covid-19's origins?

As the quest for finding the origins of SARS CoV-2 continues, it's important to be open minded. While we haven't found the SARS CoV-2 intermediate we would expect to see in the wild yet, sampling numbers or the inability to look in certain animals may mean a closer relation could exist…

Chris - And, although looking at the genetic changes in the viruses code can give us clues as to where it emerged from, David Matthews points out -

David - I don't think there's anything in the sequence there that says to you, "Oh, this has definitely been put in artificially by people." There's no secret - if you shine a light on it in a funny direction, you can see that it's been artificially made. So, the presence of the furin cleavage site, I don't think actually means anything. Other viruses have these kinds of sequences and they have evolved independently in the past in different circumstances, but exactly where it came from, I don't think it leaves us any of the wiser at this stage.

Julia - And, until a similar species in the wild is revealed, it may be hard to come to an answer.

David - Ultimately, until we actually stumble across the progenitive virus that was in an animal before it jumped into us, it's really difficult to be certain exactly how the virus made the adaptations.

Chris - David Matthews, but as Alina Chan points out, it can't be ignored that the initial epicentre of the COVID outbreak was in the very same city that's home to a world leading Institute studying these very same pathogens, and situated nowhere near where the only close relatives of the COVID 19 virus that we've found so far actually come from. Moreover, the lab, and the Chinese government more broadly, have not made it easy for the scientific community or the World Health Organization to get the answers they're looking for. Genetic databases and published theses documenting the viruses being studied in China have been withdrawn without explanation, and the publication of other crucial details germane to the story have been very slow to emerge, frustrating efforts to piece together what really happened. It's prompted some to ask, 'Well, if there's nothing to hide, why hide it?' Matt Ridley, again -

Matt - We know that information has dribbled out about the experiments that were going on, and indeed about the viruses that they held in their freezers in Wuhan. All of this could have been discussed much more openly and transparently, and it might have led to us understanding how this virus got into human beings. It might also have given us information in time to stop the virus turning into a global pandemic when it was still just a local outbreak.

Chris - We are still unable to come to a conclusion about the origin of SARS CoV-2 because certain pieces of the puzzle remain missing.

Matt - We don't know how this pandemic originated. We have no direct evidence for an animal spill over -  a natural event in a market or something like that. We have no direct evidence for a laboratory accident either. We need to find out because it's absolutely vital so that we can prevent the next pandemic, and also as a tribute to the people who have died in this pandemic.

Julia - There are questions we still need answers to, like "how did this virus get to Wuhan?" Jesse Bloom suggests how we could better understand these events.

Jesse - One way to answer that question would be more transparency with regard to both what was going on in animal markets at Wuhan and what was going on in labs in Wuhan. Unfortunately, there's a depressing paucity of information on that topic.

Julia - And we also need more time... Alina Chan.

Alina - I think that we need to be patient, because investigating the origin of a pandemic can take a long time and we can't wait to investigate the lab origin only after we have spent 10 years looking for the bat that gave us SARS CoV-2. Both have to be investigated in parallel.

Julia - While there are different proposed avenues for how SARS CoV-2 came to be (with varying levels of evidence), exploring multiple lines of enquiry might be the way forward.

Jesse- We can see that both of these are legitimate possibilities -  it's certainly possible this pandemic had a natural cause and it's possible that this pandemic was caused by a lab accident. I also think we're quite likely to see future viral pandemics, so what I hope we can do as scientists is come up with good ways to continue to develop strategies that will minimise the risk of a future pandemic ever coming from either a lab accident or from a natural zoonosis.

Chris - At the time of recording, we are awaiting guidance from the Scientific Advisory Group for Origins of novel pathogens, SAGO, who are going to provide the world health organization with recommendations for what should be done in trying to figure out where SARS CoV-2 came from and how we can prevent the emergence of new and threatening pathogens in the future. We'll keep you updated on what that report suggests.

Julia - So, at the moment, the jury is still out on where SARS CoV-2 came from, but for the sake of preventing future pandemics, we hope we can eventually get to the bottom of it.