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
I really don’t know how this plays out. We also don’t know a ton about this virus, so there’s so many open questions. I just have a really hard time making predictions because I don’t know how the outbreak is going to change.
Benjamin Thompson
Welcome to episode 16 of Coronapod. I'm Benjamin Thompson. Here I am again in the South London basement and once more joined by Noah Baker and Amy Maxmen. Hi, both.
Amy Maxmen
Hi.
Noah Baker
Hello, Ben.
Benjamin Thompson
Right, the penultimate episode then. We're almost there in terms of Coronapod.
Noah Baker
Almost there, although I think it is important to mention, Coronapod in its current form. So, we will continue doing something akin to Coronapod in the regular show that people can listen to. We might even tell you exactly where in the show it starts if Coronapod is the only bit that you want so that you can skip ahead to that bit.
Benjamin Thompson
Yeah, that's right, and that'll be coming up in a couple of weeks. Last week, we told you, the listeners, that we were doing a survey to get your thoughts and your feedback on this sort of current incarnation of Coronapod, and l have to say thank you so much to everyone who took the time to fill that in and said nice things or gave us some constructive feedback. We're going to leave that survey open for another week, and I'll put a link to it in the show notes, which you'll find either on your podcast app or on nature.com/podcast.
Noah Baker
Yeah, Amy, I don't know if you know this, but there has been a lot of responses to that survey and an awful lot of love for a certain reporter called Amy Maxmen has been coming through on those.
Amy Maxmen
Aw, shucks. That's so exciting.
Noah Baker
Yeah.
Amy Maxmen
This is like my first actual kind of podcast. I mean, you've talked with me before, but not very much.
Noah Baker
Yeah, and in fact, we have had a lot of direct requests to ‘use Amy Maxmen more on the podcast.’
Amy Maxmen
Cool, that's pretty awesome. It's really fun for me. I love it.
Noah Baker
I actually want to talk about this a little bit more, but I'm going to save it because responses to this survey are my one good thing this week.
Amy Maxmen
Cool, that's great.
Benjamin Thompson
Well, a little bit of sort of foreshadowing of what's coming later there, Noah, but for the time being, let's talk about something you've been looking at this week, Amy, and that's simulations and people trying to prepare for pandemics.
Amy Maxmen
So, there's a whole field of researchers – we can call them biosecurity experts – who are confident that a pandemic will eventually come and that it's disastrous, and they feel this is in the same category as military risks where we want to prepare the country for a war so therefore we do everything in our power to be ready on the defence and on the offence. And so, this cadre of researchers say in the early 2000s, they were thinking, ‘Okay, we do see these events happening. HIV just spilled over and other things do too. What can we do to make sure that the US is ready, and also what can we do to make sure the world is ready if various countries have versions of this?’
Noah Baker
What we're talking about today is something that's functionally different from what we've talked about a lot so far on Coronapod. So, we've talked a lot about scientists who model outbreaks to try to inform public health responses. These simulations aren't really about that. I wondered, Amy, if you could just like lay out what do we mean by one of these simulations, like what functionally happens?
Amy Maxmen
Yeah, so what happens is they coordinate let's say it's like 100 people in a room for maybe two days, and they try and get a good mix of people so it's going to be people in government and health officials and advocacy groups, businesses, big businesses, foundations, research funders, researchers. They’ll get all these people in a group, and it'll kind of begin with a newscast or something that's like…
Newscaster
‘It began in healthy looking pigs, months, perhaps years ago. A new coronavirus spreads silently within herds.’
Amy Maxmen
…so, they hear kind of the beginning…
Newscaster
‘Gradually farmers started getting sick.’
Amy Maxmen
…and they have a chance to break out and to discuss what's going to happen or how they're going to respond.
Newscaster
‘The sickest, required intensive care, many die.’
Amy Maxmen
Different groups are going to be interested in different things. Somebody from an airline is going to be interested in, ‘Listen, we don't want to interrupt our travel right away,’ and then kind of new information is given.
Newscaster
‘International travel has turned local epidemics into a pandemic spanning the globe.’
Amy Maxmen
It's kind of like a fire alarm so that you figure out, ‘Oh, I don't really know where the stairs are.’ So, it's a chance to kind of test the system and see what people aren't so fast at, what they don't know. And it's also a way of like spotting problems as they arise. And then the other thing these should do is kind of freak people out. If you get the right people in the audience, these participants who are sort of watching this play by play happen, they should be very worried at the end and hopefully that worry starts translating into policies or actions that are also funded in order to do things that prevent those problems that came up during the simulation.
Noah Baker
I have to say, Amy, that when I started reading, so you sent us a draft of your feature that you've been writing, I started reading through, it was like a proper, proper page turner for me. It's just fascinating, all the stuff that’s being done. I must admit to being almost totally naive to this entire field of research. The only hint that these kinds of sort of wargames and preparedness sort of setups happened for public health is actually from a fictional TV programme called Parks and Recreation in which this happens at one point, and I genuinely thought that was just like a funny thing they invented for that. But it's not – it's a real, very serious thing that's done in the States and all over the world.
Amy Maxmen
Yeah, that's so funny. I haven't seen that episode yet. Yeah, it's not totally shocking that you don't know about it because actually, this field of biosecurity, it's pretty small. It seems like when I'm reporting it, lots of people name the same people that I should speak with. It's not a gigantic field, but they have run these simulations with some regularity. Maybe the news hasn't reported on it, but also, I'm not sure if so much of what they found has been taken forward, and I guess that's something we can talk about. In my piece, you might have seen I started with this Event 201.
Noah Baker
What a sexy name – Event 201.
Amy Maxmen
That's sort of why I picked that one to start within the story. I don't know if you were being sarcastic when you said it was sexy.
Noah Baker
No, it really is.
Amy Maxmen
Oh, it is when you find out why. So, the reason why is that the people behind it, these biosecurity people who are behind it, they were kind of led by Johns Hopkins Center for Health Security and the World Economic Forum and the Gates Foundation. But basically, the idea is there's about an average of 200 outbreaks per year, these zoonotic outbreaks coming from nature. This is sort of a rough average right now. It's not all novel. Some of them are ones we know about. Event 201 is saying going to be one of these that's going to be the big one, so Event 201 is named after that, and in Event 201, so this was held In New York City, October 2019, so actually just last October, and that one actually was a coronavirus. So, it's a novel coronavirus. It emerges in Brazil. Bats are the reservoir and from bats and moves into pigs and then it moves into farmers, and farmers carry the virus to a mega city in Brazil, where there's an international airport and there we find out later that there's travellers who had travelled with the virus to the US, to Portugal, to China, and within 18 months, this coronavirus has spread around the world with 65 million people dead and the global economy is in freefall.
Benjamin Thompson
When this sort of scenario is being played out, are the decisions that the people there are making, does that influence how the outbreak continues at all?
Amy Maxmen
That's a great question, and to be totally honest, I'm not totally sure if what they say influences the trajectory of the simulation that of course has been planned in advance, but there kind of are breaks where they get to discuss things, like, for example, I hear it comes up in every single simulation, that there's big pushes for travel bans for like the main thing everybody wants to do. But the biosecurity field has like looked at enough outbreaks to realise like for respiratory pathogens especially, travel bans tend to not be fully effective. They also are debated because there's so many economic consequences and things like that. But then also we know it's not a full block. So, maybe the decision will be ‘Alright, let's have a travel ban,’ and then they'll say ‘Newscast: Guess what. The travel ban didn't fully protect you from this outbreak. It's still spreading in your country.’
Noah Baker
It's really a bit eerie to hear about Event 201 and this simulation because right now, we have a coronavirus, a novel coronavirus, that was zoonotic, that arrived and then spread quickly, and we're six months in and we're looking at half a million people that have died, and this is 18 months in and 65 million people have died. You can't help but sort of like morbidly see a path where our current real life outbreak could continue to mimic what happened in the simulated Event 201 outbreak. Whilst we're in the middle of this outbreak right now, it makes me think okay, cool, so surely given that we've simulated something that seems eerily like what's happening now if not on a broader scale, everyone's going to be paying a lot of attention to that simulated outbreak where this has all been planned and those things that happened in that simulation are happening now. But that's not really what's happened in real life. People haven't really paid attention to what happened in that simulated outbreak.
Amy Maxmen
No, I don't think they and, talking with the people in this field, they're having a lot of sort of moments of recognition. Tom Inglesby at Johns Hopkins is somebody who's led a number of these simulations, and one thing he was telling me was, it's very frustrating to kind of know certain things, and it's not just from the simulations. Of course, their simulations are informed by how much they've studied past outbreaks, so he knows very well that, with anybody actually who's really looked at outbreaks closely, they move so quickly that if you're not super fast, you're really in trouble. So, in late January, he wrote this extremely long 27-part Twitter thread that's like, here's a list of actions we need to take right now. And this was back when you know, the US was talking about travel bans.
Noah Baker
I think that's one of the really interesting things is, with the benefit of hindsight, people can say, ‘Oh, obviously, that was a silly thing to do at the time.’ But people like Tom Inglesby, they predicted these things a long time in the past. In fact, we have a recording of him saying this when you interviewed him.
Tom Inglesby
I wrote an article in Foreign Affairs right at the end of January saying we need to start preparing for responding to a pandemic. So, even though it was ‘in China’ at the time, it was pretty clear that, ‘Okay, we need to start preparing our hospitals, we need to start preparing our public health systems, we need to ramp up vaccine science, we need to get our diagnostics together, we need to figure out what we're going to do about international travel because it's all going to come crashing down.’ And the reason why we need to go through that list was because we've gone through this within an exercise as many times. I think it helped us and I think exercises that helped others basically begin to see the dominoes that will fall.
Noah Baker
Dominoes falling is such a good analogy there or metaphor there, I think, for what we then saw happen immediately after that moment in January where he spoke out.
Amy Maxmen
Yeah.
Noah Baker
Given that these wargame-like scenarios have been done for a long period of time and they are there to sort of plan for what might happen, I'm kind of interested to know how accurate does it seem the sort of suggestions and the advice that come out of those simulations are? Do they help come up with potential bottlenecks, problems, things that we could have acted on? If people listened, would it have helped, is the question I guess I'm asking.
Amy Maxmen
As far as the advice goes, yes, I think the advice that the people in this field are giving has been pretty solid. I would say if that was heeded, it would have been great. A lot of times, kind of just discoordination shows up, like who's leading this, and that was a big one that came up in a lot of the simulations in the US. There was a simulation last year called Crimson Contagion, and that one also pointed out who has the authority to lead a pandemic response. And for something like that, I don't really see strong signs that that was really taken forward because some of the simulations afterwards, the recommendations are we need to strengthen our public health system, strengthen coordination between public health departments in states and federal, and I don't know of any signs – and neither do my sources – of that really being taken forward in a way that was really serious. In fact, we know that public health departments have actually been defunded over the years and the CDC has been stable or had a lack of funding.
Benjamin Thompson
Okay, so a fair few bits of advice that don't seem to be heeded, but is there anything that is listened to?
Amy Maxmen
People are always like, ‘Where's the vaccine?’ That happens in like every simulation, so they always kind of end with a lot of discussion about we either need to stockpile vaccines – because the simulations were split, sometimes the simulations were bioterrorist events where somebody introduces something we already know like an influenza or a smallpox virus – and so in those cases, it would be like we need to stockpile the vaccines we have or think of programmes to accelerate our influenza vaccine machinery. That's been taken forward, pretty much, I think, every time these come out. There were times when we stockpiled smallpox vaccines and anthrax vaccines. Most recently, this year, President Trump announced a program to accelerate and refine influenza vaccines. So, that part does seem like it was sort of taken up a little bit more. But sort of the middle game… I like that phrase. One of the people I spoke with, Jeremy Konyndyk from the Center of Global Development, he mentioned this middle game, and he felt like that part was always neglected after these simulations. There's the point of containment where you want to make sure that the virus, if it gets into your country that you kind of clamp down really fast, you test people, you get it down really quickly like some countries have done, in this case. So, that's the first game. You want to make sure you've got your systems up and ready for that. And then there's the end game, which is the vaccine. But that middle game, what do you do when there's just so many cases that actually it's really hard? And he said, that's all just a matter of scale. That's like, can you get enough diagnostic tests? Can you get enough contact tracers? Do you have enough places for quarantine? So, he felt like that middle game has always been really neglected, so it would come out in the simulations, but nobody really did much with it.
Benjamin Thompson
You're talking a lot here about simulations done in the US, and then there was this criticism of the mid game, as you say, there, but what about other countries? Presumably, they're doing these simulations too, and are they actually taking any concrete steps to avoid some of those criticisms?
Amy Maxmen
So, I have to admit that I don't have endless time, and this could be like a very long piece, so I didn't look at every country. However, I did look at a few things. One, is there's been some international-level simulations that bring together global bodies, like at the World Economic Forum, they've run a number of simulations, everyone at Davos, and those have looked at what is global coordination like, like what happens when every country is vying for the same supplies and what happens when you need to have a vaccine that the whole world can use. So, that's come out in some of these big simulations. There was a couple of them in 2017. Some of those things, again, were sort of taken forward just because of the simulations, also just discussion around this. So, for example, there was the Coalition for Epidemic Preparedness Initiative (CEPI). It coincided with these simulations, but it was also sort of the Zeitgeist of the time. This was just after Ebola, and everybody said, ‘Oh my gosh, if this much havoc can be created by an epidemic that's just in these three small countries that don't have a ton of international travel in, Sub-Saharan Africa, what are we going to do in a pandemic?’ So, that was sort of taken forward a little bit. There were other networks that kind of started up, ‘Can we have more partnerships between countries?’ But the person I spoke with about this he was just saying the network's they were working on, kind of in retrospect, he's just saying they were not commensurate to what we need right now. The other thing that another researcher brought up was the case of Taiwan. They ran at least one simulation that was like all hands on deck, different parts of the government, and they had a system for what exactly where they were going to do and they practice this very seriously every single year. So, when this outbreak was escalating in China, Taiwan took it really seriously. They’re right there. There's obviously tons of travel between the places, between Mainland China and Taiwan, and they've been practising these systems for 17 years. So, as soon as it happened, everything kicked in, and they've had only seven deaths from COVID to date, which is incredible, especially thinking about their proximity to where this all started.
Noah Baker
This is something that we've talked about and, full disclosure, I'm about to do a little bit of speculation, but it's something that really stands out to me whenever I think about this sort of thing. So, Taiwan, Hong Kong, China, Singapore, have done amazing jobs of containing this outbreak which originated so close to them. And one of the things that lots of people have said, and we’ve said it on this podcast before, I've said on this podcast before, is that they have this very real memory of SARS in their head and that it would make sense that that would be something that's very present in everyone's minds, and that's why they might take this very seriously, very quickly. One thing that you said right at the beginning of this is that part of the point of these simulations is to get influential people into a room and scare them, right, is to make them scared and realise how bad this could be. Are these simulations not scary enough? Because it doesn't seem like these people are scared. But if you kind of look at this maybe anecdotal evidence that countries in East Asia that have recent memory of SARS in the head and countries in Western Southern Africa, who have Ebola ringing in their ears, they took it real seriously, real quickly, and they've had better outcomes. I mean, certainly in East Asia, there's been much better outcomes. Maybe these simulations need to be a hell of a lot scarier.
Amy Maxmen
I know, I wonder. I talked about that was Tom Inglesby and he felt like at every simulation, everybody in the room was really shaken. So, what I've heard is there might be two problems. One, who is in the room. So, the person at World Economic Forum I spoke with, he was realising that the people who he was talking with who were making these plans, maybe they're the people who were in charge of supply chain or something, but they weren't the CEOs of the company. In retrospect, he's thinking they might have been the top managers for what they're doing, but the CEO might be listening to someone else. So, in the end, it's one, who's in the room during the simulations. And another thing is, if you are a politician and you're a governor or the president, you want to get elected again, and a lot of people, and this is what Tom Inglesby was saying, is a lot of people might think they can go ahead and have their four years without a pandemic on their watch. No one's going to see these simulations. No one's going to see your public health system strengthening. That's in the background. You might be more likely to win votes if you're going to do things that people see, like reduce taxes, build roads, that kind of thing. This is sort of invisible work until it really, really, really matters. And if you're rolling the dice, you might get by without one.
Noah Baker
Yeah, I mean, it's interesting, in your in your feature, you mentioned that there is something called the Global Health Security Index that was published last year, and it rated 195 countries around the world for how prepared they would be to prevent, detect and respond to an outbreak. And of all of those countries, although none of them did particularly well as far as I can see from your reporting, the US was ranked number one and the UK was ranked number two. Now, if you look at our actual responses in the UK and the US, I don't think by any metric you could argue that the two of us have ranked number one and number two in terms of managing these outbreaks. So, it begs the question of just because we might have some preparedness there, we might have the resources and the ability, there's something else that is getting in the way there that is preventing that successful response.
Amy Maxmen
Yeah, and this gets into blind spots. So, there were some things that people have been truly surprised by, and I think the response and the magnitude of the outbreaks in the US and the UK has been really surprising to a lot of people. And I think this will be written about for a long time, but one of them is certainly what to say about leadership. In the Global Health Security Index, they have one metric relates to how corrupt the government is because there are measures for that, but they never kind of accounted for what if you have a leadership that is actually working contrary to the public health response? And we know that we've had leaders now that contradict public health advice, and there's a lot of signs that President Trump has also suppressed the CDC. The CDC has been very, very quiet during this outbreak and Tom Frieden who was the former director of the CDC, he said that's a direct result of the Trump administration. That's something that they didn't account for. In their models, everybody is worried when there's an outbreak and everyone's doing what they can. Now, there's all sorts of problems, but they weren't expecting that. Then the US had this big problem with testing right where we were way behind on tests. In the joint external evaluation and in the Global Health Security Index, they look at the US immense laboratory capacity. They look at our private sector, thriving private sector, tons of capacity to make diagnostics. They look at various networks we have. We have societies that connect public health laboratories. And they said, ‘The US is going to be fine when it comes to detecting a novel pathogen.’ And that turned out to be just wrong. We're slow. We're really, really slow.
Noah Baker
Perhaps that speaks to some of the things that you've mentioned previously on Coronapod. So, the stumbling blocks like having to have hospital computer systems that properly mesh. Those were the weird stumbling blocks that are in the way that perhaps wouldn't have been taken into account when these metrics are being made.
Amy Maxmen
Right.
Benjamin Thompson
We’ve been talking a lot about simulations here, and it seems that the people who have been running these are acutely aware of some of these issues and some of these dominoes that were to fall and seem to have fallen. I mean, did you get the sense from them that they're really frustrated? That all of their work that suggests, this is what you should do and other countries have done simulations and this is what they have done and it's worked. What do you get a sense from them about their feelings about it all?
Amy Maxmen
Yeah, it's so funny. I don't know. I think other people who are journalists will relate to this. I talk to scientists and often spell things out very carefully, and then sometimes I’ll be like, ‘How do you feel?’ And they'll like give you this intellectual answer. And I'll be like, ‘Yeah, but how do you feel about this?’ And yeah, they don't feel good. They feel bad, of course, but they're still trying. They still want to do something. Johns Hopkins is trying to put out helpful databases for showing information to the public. And also, can we help provide instruction for county health departments and public health departments and states that aren't sure what to do? Can we coordinate that better? So, they're still trying but, yeah, it's a moment of reckoning to be sure.
Benjamin Thompson
Does the kind of availability of data right now and sort of moving forward, does that mean that we don't need to run any simulations again because we are kind of living the reality of it right now?
Amy Maxmen
Yeah, exactly. I think that's what I heard across the board, is, well, we're not going to have to run a simulation for a while because, first of all, the whole impetus for making people worried, hopefully, that's there. And then there's these kind of exercises after the event where you can really just sort of go back and look at all of these pieces, all of those dominoes that fell and sort of look at what happened, why it happened, how it could have happened differently.
Benjamin Thompson
I mean, it comes back to something that Noah said several times, and I think it's worth saying again, all it's taken is a global pandemic with, what, over 10 million people infected and thousands of people dying and to sort it out, and it’s just so frustrating.
Noah Baker
For what it's worth, in the Parks and Recreation episode when they do their pandemic preparedness, Leslie Knope is forced, in the end, to deliberately tank the entire city and cause everyone to die so that she can get away to get to a fundraising gala that she really needs to get to.
Amy Maxmen
Laughs. Oh my god.
Noah Baker
I wouldn't recommend that in these very serious and important exercises are being carried out.
Amy Maxmen
That's funny.
Benjamin Thompson
So, well, let's leave the discussion there for the time being team, and let's move on to one good thing, where we take a look back over the past sort of seven days or so at things that have made a smile, I suppose. Who would like to go first this week?
Noah Baker
I, if it's possible, would like to jump in first, partially because I have already previewed what my one good thing is and so I'm sure listeners are on the edge of their seat to hear it. But I want to come back and say the survey. A lot of people have written in and that means an awful lot to us at the Nature Podcast team, partially because it allows us to learn how to grow in the future, which is brilliant, but also because, to be honest, this was a bit of an experiment for us. It's all been recorded from our makeshift studios across multiple different countries. And it's really nice to hear when people enjoyed what we did or they were pleased by what we did. It's validating, just personally for me, validating to hear people really liked it. And one thing that a lot of people said is they liked this segment, so I thought it's important that we have a one good thing this week. And also, I want to personally apologise that we did not have a one good thing last week. There were some technical problems. We actually did have one good thing last week, but we had to cut it from the show or I had to cut it from the show when I was editing it because the audio went all squiggly and horrible, and you wouldn't have been able to hear what it was. And so, I don't know whether or not Amy has a one good thing from last week that she said. She might not want to say it again, but it was a really good thing and I would encourage you to bring it up again, because it's a really good thing and we missed it last week because of audio glitches.
Amy Maxmen
Well, I also am super excited that you got positive feedback. That's really nice to hear. I love it. That's very encouraging. But yes, big picture, more important big thing from last week, the Ebola outbreak in north-eastern DRC was declared over, finally. It had begun in August 2018 or at least that's when it officially began and it infected almost 3500 people and it killed 66% of them, so a large number. And it was, I don't know, it’s called like the most complicated outbreak yet because it was in this area that had 25 years of ongoing, horrible, horrible conflict and political instability, so it was really difficult. I actually went there this time last year with the director general of the World Health Organization, and it was an incredibly difficult situation, and I saw incredibly dedicated people. I got to speak with some of them when I wrote a quick piece for Nature about the end of this outbreak, and so they're extremely happy to at least have seen their hard work pay off and it’s sort of bittersweet because they've quickly moved on to another Ebola outbreak that's been declared in the west of the DRC or they've moved on to the COVID response, most of them to the COVID response. But it is great to see this end.
Noah Baker
Hear, hear.
Benjamin Thompson
Hear, hear. Good news all around. Well, I'm going to bring it home then with another flippant example. I always set myself up like this. Amy, you bring something quite important and I come in with something absolutely nonsensical. I'm not sure this is a good thing but it's a regular thing. So here in the UK then, we marked – I’m not going say celebrated because I don’t think that's the right word – but we marked 100 days of lockdown last week. And a good friend of mine, he owns a baffling amount of t-shirts, like over 300-odd, and every day during the lockdown, he's been wearing a different t shirt, and he's been instagramming it once a day. And it's just, it's just a nice anchor point in the morning. So, on the hundredth day of lockdown, he wore one that had a tie on it but a picture of Yogi Bear wearing a tie, so that was his effort there. And I look this morning and it was all about the J-pop band Perfume. So, I think they're of variable quality, but I hope that we can stop this game soon, but I love that he's doing it.
Amy Maxmen
Does he have 100 t-shirts?
Benjamin Thompson
300.
Noah Baker
300 t-shirts. I think I have about six.
Amy Maxmen
I don't know. Okay.
Noah Baker
The listeners won't be able to see, but Amy and Ben can see that actually Ben and I are wearing more or less the same t-shirt today, which happens quite often.
Amy Maxmen
It's one of those like joke prison shirts, like if you drew a prison cartoon character from like the 1920s. That's what you guys…
Noah Baker
A Bretton top is the official, classy distinction.
Benjamin Thompson
I'll have you know, I mean, this is this is very much a Bretton shirt that I'm wearing. How dare you. Well, let's, let's leave it there then this week. Thank you so much for chatting as always, and I'll see you next week for the final version in this current guise of Coronapod. Thanks both.
Amy Maxmen
Thank you.
Noah Baker
Thanks, Amy. Thanks, Ben.
Benjamin Thompson
More from Noah and Amy next week. Look out for that feature on pandemic simulations, which Amy has co-written with our colleague Jeff Tollefson, over at nature.com/news. Up next on this week's show, we've got a quick roundup of some of the coronavirus research that's been published around the world in the past few weeks. I'll put links to all of them in the show. notes which you can find in your chosen podcast app, or over at nature.com/podcast.
Benjamin Thompson
First off in this roundup is a pair of papers published in the journal Cell. Two teams have developed a shortcut to generate COVID-19 mouse models using a harmless virus to make the mice susceptible to infection. The SARS-CoV-2 invades human cells by attaching to receptors on the cell surface, including one called ACE2. But mice have a different version of ACE2, which makes them impervious to SARS-CoV-2 infection and so pretty useless for studying the virus. Now, there are transgenic mice that carry the human version of ACE2. These mice are susceptible to infection, but they're also scarce. To develop a more widely available mouse model, teams in the USA and China, used harmless adenoviruses, a workhorse of gene therapy, to deliver the human ACE2 gene to the lung cells of mice. Then the mice were exposed to SARS-CoV-2 and showed signs of infection, losing weight and developing pneumonia. The ill mice could then be used to test therapeutics, including antibodies and an experimental vaccine.
Benjamin Thompson
Next up, over 40% of COVID patients in two new studies showed no symptoms of the virus. According to one of the teams, this could be an important source of transmission. Early in the global COVID-19 outbreak, Vietnam began to repeatedly test people at high risk of infection, including those without symptoms. A team of researchers monitored 30 individuals who were found to be infected. Their results published in the journal Clinical Infectious Diseases revealed that 13 of these people developed no symptoms. The research teams say it's highly likely that two of the asymptomatic individuals were the source of infection for at least two other people, despite nasal swabs showing they had lower levels of viral RNA that infected people who felt ill. A similar story was seen in Italy. Researchers carried out mass testing of the citizens in the locked down town of Vo’. They found that just over 40% of those who were positive for the virus showed no symptoms at time of testing and didn't go on to develop them afterwards. This work was published in Nature.
Benjamin Thompson
Research published on the preprint server medRxiv suggests that when it comes to testing, frequency matters more than sensitivity. A team from the Harvard T.H. Chan School of Public Health modelled testing strategies to work out which would be most effective in communities such as universities, where COVID-19 cases could quickly spiral out of control. They found that regularly testing large numbers of people is a powerful way to control spread even if that means using a relatively insensitive test. The most accurate tests are based on PCR, but they are expensive and slow to return results, which is not ideal for surveillance testing. The authors show that weekly surveillance testing paired with case isolation limited an outbreak, even if the testing method used is not super sensitive. By contrast, only testing every two weeks allowed the total number of infections to climb almost as high as if there was no testing at all. These findings have not yet been peer reviewed.
Benjamin Thompson
That's it for this roundup of the latest coronavirus research. I'll put links to all of these papers in the show notes. And that's also it for this week's edition of Coronapod. As we talked about at the start of the show, if you've got a couple of minutes’ spare and could fill out our survey, that would be amazing. Listen out for a corona-free edition of the regular Nature Podcast on Wednesday, and we'll see you back here in seven days for the final edition of this incarnation of Coronapod. I've been Benjamin Thompson. Thanks for listening. Stay safe.
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