Ducks Unlimited Podcast

00:00 Mike Brasher So today we have a really special opportunity, a really special guest joining us here. It's an opportunity for us to continue a conversation about a topic that is of great relevance to Ducks Unlimited. We've gotten involved in this over the past eight to ten months really, and that's the topic of highly pathogenic avian influenza. We've had a number of opportunities to engage with experts in the infectious disease field, mostly in the wildlife space, and that was largely related to our desire to educate our members, largely mostly waterfowl hunters, about this issue, what they needed to be doing, the precautions they needed to be taking, and also educate people on the potential risk to wild waterfowl populations, and then its risk to poultry, backyard poultry, commercial poultry. The virus and the disease that it causes have continued to exist over the past several months, really since it started, since we began to see it here in the U.S. last year, and questions have continued to evolve around risk to human health and other animals. So we have here an opportunity to welcome in a global expert in this field. Dr. Richard Webby is a faculty member of the St. Jude Children's Research Hospital. Dr. Webby is also director of the World Health Organization Collaborating Center for Studies on the Ecology of Influenza in Animals and Birds. I think you've just overtaken the previous person that had the longest title for any introduction we've given in an interview, so congratulations. I had nothing to do with the name. So it's great to have you here. Also helping us moderate this question and answer is our Chief Conservation Officer, Dr. Karen Waldrop. Karen, welcome. Another guest in here with us is Chelsea Bryant, also with St. Jude. So thank you, Chelsea, for being here. And I think to start off with, we want to, I guess Richard will give you an opportunity to introduce yourself. People will hear you talk and they'll hear a bit of an unusual accent. And so you can tell us where you're from, tell us what you do with St. Jude, and then any kind of connection. We were initially surprised to learn that there is a global expert in avian influenza

02:18 Dr. Webby at St. Jude. So a little bit about yourself and what you do at St. Jude. Yeah, so more sort of my history, I guess. I'm, as you said, from the accent. I'm clearly from the south, so I'm from Mississippi. I actually live in South Haven, but yeah, originally a New Zealander. So I did my studies down in New Zealand on viruses. I did my PhD and was sort of looking at the big wide world to come and sort of move into a virus that was sort of medically relevant. And so I sort of, there was a gentleman by the name of Rob Webster who was sort of one of the granddaddies of the influenza world. So he was one of the people that actually discovered that it was the wild waterfowl of the world that where flu really comes from is from that host that they sort of spill out everywhere else. And as it turned out, he had a research program at St. Jude Children's Research Hospital in Memphis. So it sort of gets the question of St. Jude, a pediatric children's hospital with someone studying avian flu makes no sense. But when St. Jude started, 75 or how many years ago it was now, a lot about what we were learning about how cells turn into cancerous cells actually came from the study of viruses. A lot of the first oncogenes were a viral oncogenes. There was a natural combination of virology and sort of study of cancer. And so they recruited a lot of virologists at St. Jude. And if we look at our patient population, what really gives the most risk to our kids is actually infectious diseases. So there's a couple of links as to why this program is at St. Jude. And so I came back actually in 1999 to my position actually at St. Jude was funded by a grant. Rob Webster had just got to study a virus called H5N1 that was just emerging in Hong Kong. So I sort of came to St. Jude in the era where the virus we're talking about now, it's great, great, great, great, great granddaddies, which are starting to emerge. So yeah, that's a long-winded way of me saying that's how I came from New Zealand to Memphis, Tennessee. And

04:32 Mike Brasher that was 23 years ago now, I'm still here. People from here in Memphis, depending on what news station they watch, they may see you every now and then on the news talking about sort of the annual human influenza virus. Your lab does a bit of work in that regard too, or at least you're familiar with some of the processes by which vaccines are identified to match the currently

04:53 Dr. Webby circulating dominant strain for human influenza virus? Yeah, that's right. So the St. Jude, that's that long-winded name you said, the WHO Claiborne Center for Studies in the Ecology of Influenza in Animals and Birds. So that particular center is housed at St. Jude. And within the group within WHO in Geneva that we're associated with is the Global Influenza Program. And it's that program that makes the global recommendations or the twice yearly recommendations for what goes in that flu shot. And so that group started off with a couple of groups, sort of what they call collaborating centers. So started off with one in London, the US CDC, and about the mid 1970s they realized they needed a little bit more expertise in that network on more of the animal influenza. So the avian influenza, sort of Rob Webster, as I said, was one of the leaders in the field. So they came to St. Jude and asked if there'd be a collaborating center within that. So it's grown a bit since then. There are now seven of these collaborating centers. But we travel a couple of times of the year to Geneva and sit around the table and take part in those discussions about what flu viruses are out there circulating now, what are our current vaccine strains, and trying to sort of do a little bit of that crystal ball gazing, what's going to be their next flu season, and to make sure to try and get the best vaccine antigens in the vaccine. So yeah, it's sort of

06:21 Karen Waldrop interesting part of what we do. Karen, I think I took one of your questions there. I think it's perfectly fine. I mean, that's great to get that kind of overall, like on an annual basis, and influence and with how your lab works. How about how your lab works in regards to avian?

06:36 Dr. Webby St. Jude's had a history of working in this area for a long time. So right now, a lot of our funding for our research comes from the National Institutes of Health in the US, and we're actually funded as a center of excellence for influenza research and response. So within this funding, the goal is to really provide a research understanding of the pandemic threat posed by some of these flu viruses in the animal populations and do sort of what we can to prepare for them. So I'm a virologist, so we do a lot of virologic studies on viruses from both from avian hosts and from swine hosts as well, and characterize. And we come at it from, unlike sort of Dave Storknick, who I know you've had on here before, comes at it from sort of the more wildlife perspective. We come at it from the other side, sort of the human health perspective. So what viruses are out there in these animal populations? Which ones probably cause the most threat to humans? How do we assess that risk? And how do we get better at doing that? And then how do we sort of develop ways that we can actually reduce the risk and do something about it?

07:49 Karen Waldrop That's great. And you mentioned Dr. Dave Storknick, who's been on the show before, on the podcast before. And so we've actually had multiple podcasts where we've talked to experts about avian flu. But for those that might not be familiar, would you mind providing a brief introduction as to what is avian flu? Where did it come from? Maybe a little bit about how it's

08:08 Dr. Webby transmitted and then the current situation. So I think sort of avian flu is actually a terrible name for this particular virus we're dealing with now. So it's this H5N1. So maybe just step back a little bit more to answer your question. So if you look at influenza, I know we're so, we tend to associate with it sort of the sniffle and cold and severe disease we can get during our winter months. But if you look sort of ancestry to all the strains of influenza that are either in swine or in humans, they all started their life actually in wild, primarily waterfowl populations. So that is the natural host of influenza. And within that population, there's this whole soup of flu viruses from all sort of different shapes and flavors. I think, yeah, I think to put that into context, if you think of COVID-19 and the SARS-CoV-2 virus, we think of sort of variants. I think people are familiar with variants emerging. If you think of that sort of supersized within wild waterfowl population with flu, that's kind of the situation in there. So that's where they circulate. It's a virus that sporadically pops over, of course, from that host into other hosts, whether it's domestic poultry, whether it's swine, and sometimes they find their way to humans. That's sort of the natural lifestyle cycle of these viruses. So where this particular virus is that we're sort of worried about now, within the soup, we sort of classify the super viruses. We're lab scientists. We're not terribly innovative. So it's H1 through H15. We group them into that. This particular virus we're talking about now is an H5. So it's a particular group of virus. We first saw this virus, meaning when I say this, meaning the one we're worried about now, in the live poultry markets in Hong Kong back in 1997. I know, it's a lie, actually. That was the first time we saw it. They subsequently found it for the first time, actually, in southern China, in a goose in southern China. It's sort of a famous virus, a goose, Guangdong one, 1996. I remember that one. But yeah, so that virus found its way into the markets in Hong Kong. At that stage, nobody knew that avian viruses could actually directly infect humans. Back there in 1997, in the live poultry markets, there were 18 people that were confirmed infected with that virus. Six of those actually died. That was really, I think, the field really began to understand there is a threat, direct threat from these avian viruses to humans. That virus, they depopulated all of the poultry in Hong Kong. That particular virus went away, but it was still circulating in southern China. It sort of stayed underground for a few years, circulating in that region. In the early 2000s, it started to spread out. So throughout Southeast Asia, through into Vietnam, Thailand, et cetera. It again stayed in that region for a number of years. In the mid 2000s, 2005, it got into some of, into Qinghai Lake, which is a major lake in China, where sort of a segue to birds that migrate through to Europe. So it got into that environment, and that's when the more global spread happened. About transmission from… Yes. If we can stick to bird to birds, we'll go further on into that later. So again, if you talk about the sort of annual, sort of just run of the mill, normal avian flu virus, so maybe not this one, but say, pick your other favourite H type, B and H4 and H6, for example. That particular virus in waterfowl, we think, is more of a fecal-oral route. So the virus tends to be more of a GI infection in waterfowl, and so that's the route. Exactly how it spreads from

12:04 Karen Waldrop bird to bird is a little unclear, but that's the contaminated source. So maybe the habitat use of waterfowl and feeding behaviours being in shallow water and being in the box helps to…

12:14 Dr. Webby The dabbling ducks are more susceptible to diving ducks, yeah. But yeah, and of course, this particular, I think it's a little less clear right now what this H5N1,

12:23 Mike Brasher I think there's probably a little bit more respiratory spread with this particular virus. One of the things that you bring to this conversation, Richard, is a more global perspective. As we've talked about, we've had a number of guests that have a more North American focus, but we've been trying to schedule this conversation for probably three months. The first time, the first set of dates we tried to identify you were in Geneva. Second set of dates we identified you were in Brazil. So I'm curious of your perspective on sort of the global view of this, the relative risk, the way it's being viewed in different countries, maybe in comparison to North America. Kind of just give us a sense of the tone of the conversation from a global perspective.

13:08 Dr. Webby Yeah, so I think the tone really has changed, at least if we're talking the Americas, Europe and Africa, with this particular form of this H5 virus. So something happened in probably mid-2001, where this particular virus that was circulating did something that made it, I think, a little bit more fit for wild birds. And so Europe up to that point had, this wasn't a virus they hadn't had, right? But it would be more seasonal. So as the birds migrated through, they would get spillover into their poultry populations. So it was more of a seasonal thing for them. In terms of Africa, it's probably, with the exception of Egypt, where it was endemic in their poultry, probably something similar. But sort of post-mid-2001, they're now, I think, facing the fact that they're in an endemic situation. So yes, for them, they're absolutely, this is a major issue for that, both industry but human health as well. And of course, for the Americas, we just haven't had it before all. So for us, and South America, of course, is now dealing with it. And I don't think they really have much of a feel for how widespread it is down there. And my gut feeling is Africa is also the same. This virus is now probably set up shop in a number of places in Africa. And so it's very much of a different feel now than we were two years ago. You described it as being endemic. What exactly do you mean by that in terms of how we can expect this virus to persist going forward? What does that mean in the biological sense? Yeah, so I guess because it's endemic in probably the wild, the migratory birds within some of these places anyway, but prior to that. But I think even within some resident bird populations, so it's not, so when the migratory birds sort of move away, historically the virus is gone. But I think it's more that's actually stayed over a couple of those seasons now in Europe. So again, resident populations of birds, whatever they be, sort of maintaining it locally as well. So what does that mean longer term? I think it's, at least for Europe, in Africa, it's more of a year round concern now. So there'll be local spread, probably as migratory birds move back and forwards, they may bring slight variations of it with them, so seed new outbreaks. And for, of course, us, it's a night and day difference. Thinking back to 2014, 2015, where we first saw this virus in that part of the world. Now it came in via the left coast, but for whatever reason, we don't even know, didn't make it through the summer months. But now, I think even this virus died out in the migratory birds for whatever reason, I still think it would still be here. So maintaining other populations of birds. You think this virus will persist in wild waterfowl populations for the foreseeable future? This subtype? Yeah, and then the subtype, it could change, right? So that's one thing about flu. It does continually change, so it may change form, but I find it hard to imagine this virus

16:35 Mike Brasher going away this time. And I guess we'll transition here to talk about what we saw in waterfowl. Last year, beginning in October, November, our phones started blowing up from a lot of our members, waterfowl hunters that were seeing snow geese, Ross's geese, die in alarming numbers, sick, dying in alarming numbers. But then around mid-December, we began to, our state partners, federal partners, our waterfowl hunting members, started to notice a pretty significant decline in symptomatic birds they were observing in the field. And it seemed to be pretty prevalent, pretty prevalent observation. How do you describe what was going on there? Is that a lot of people had surmised that that was the time frame over which the more susceptible birds fell ill and died, and then there was some immunity that was developing. What do we think, or what do we know now with a few months behind us, was happening and why we saw that decrease

17:37 Dr. Webby in December? Yeah, so I think it's almost certainly due to a build-up of immunity in those populations. And I think there's some solid evidence coming from people like Dave Storbnick who are looking in these populations that there is now, at least some of them, a good level of immunity to these viruses. But we've got to think that at any infectious disease, whether it be COVID, whether it be influenza, at any population, whether it be humans or a bird or, again, pick your animal, there's always going to be a spectrum of severity of disease through those that die because of it. But there's always going to be survivors, whether they just don't get the same dose of virus, they have something about their genetics, they're just not as susceptible. As you say, I think that the most susceptible birds were killed, but there were many that were infected, developed immunity to that virus and survived. And so I think that's probably the transition point that we saw from lots of die-off to now not as much. And I think we may come to those questions later on, but I think it also brings up lots of questions about what does that do to the virus itself? Does that mean it's going to go away? No, I don't think so. Does that mean it's going to be harder to find the virus? Maybe. So lots of questions surrounding that. But yeah, to direct answer that question, I think what happened, population immunity just built up

19:05 Mike Brasher and therefore we didn't see the mass die-offs. So Karen, this is probably a good place for us to ask about your expectations for what we may see this fall when waterfowl populations begin to migrate south again. I think you'll be the first person that we will have the opportunity to ask that question of among the experts that we plan to talk with. So last year when the virus was circulating, there was, in my understanding, pretty much there was very little immunity or prior exposure, whether we're talking about adult birds or juvenile birds. Now we're at a point where we have a lot of adult birds that would have been exposed to it last year. So there's a question in there about what do we know about duration of any of the immunity that they would have acquired, how long that would persist. But then also, given the expectation of this being

19:56 Dr. Webby endemic now, do you think we will see similar levels of mortality and illness among young birds if you had to handicap it? What's your expectation? Yeah, I think that's a hard one to answer because if you think about, again, a population, mortality in a population, it sort of is a mix of sort of the susceptible birds in that population, but you also have to have enough density of birds that are susceptible for it to spread as well. So clearly if a hatchling animal bird is infected, there's a good chance it may die, but whether there's going to be enough of that virus in the population to pass from that to immune adults through a population I think is a little bit unsure. So whether it be the mass die-offs in that population or just sort of scattered deaths, I don't have a good feel for. I think the virus will probably move down with those birds in some form or another. It's quite interesting and we've been doing, so we, Rob Webster, has been doing studies in a couple of populations of birds in North America for close to 50 years now. One is actually in Alberta, so in sort of mallards and pintails as a sort of marshaling to fly south, we team up with the Canadian wildlife folks there and they, as they're banding birds, they'll swap them and send them to us. And actually right now we have teams in the Delaware Bay region in New Jersey, so sampling of sort of fecal material from the shorebirds that are stopping off from their migration to feed on horseshoe crabs, eggs. I don't get a long-winded way of getting to your answer, but if we look at those populations and we look for viruses all the time, you know, we almost always see viruses in those populations. Some years we'll see lots of virus, some years not so much, at least particularly in the Delaware Bay site. For many years it's sort of cycled, so from high prevalence to low prevalence to high prevalence to low prevalence. Since Sandy it's been a little bit messed up, Hurricane Sandy. But also we see different viruses every year, so it's not like we see the same viruses every year. Sometimes we see some, sometimes we see another. And so I get to the point of we don't really understand how viruses are maintained in these populations, probably enough to make the predictions that everybody wants. What is going to happen to this? Is it going to come every year? Is it going to come every other year? Yeah, how long is this immunity? So do we get a period where immunity is high, so virus prevalence will stay low, but then it wanes over the course? When you have a naive population. More naive and bang, we get another burst. So these are questions we don't have answers for, but again my gut feeling is this one is different than most of the other viruses that we have in this population. So even patterns we've seen with other low path flu, we can't necessarily translate to this one. But I think it'll stay. I think we'll see it come down with birds when they come back down. We'll see spill over at domestic poultry, but maybe on a

23:05 Karen Waldrop smaller scale than certainly we've seen in the past couple of years. You said, you know, as far as what you're starting to see with this, another thing we're starting to see a lot more infection in mammals. You're hearing a lot more reports, sea lions, otters, mink, fox, bear, you name it. You know, the national media is reporting on this a lot more. So the general public is hearing a lot more about it. I guess the question is, can you provide an update on our understanding in this regard as far as, you know, this is bird flu, right? And so why are we starting to see some of this as far as in mammals and why are they contracting the virus?

23:43 Dr. Webby We know this is a virus that is really supremely sort of fit for birds, particularly waterfowl bird, I think. It's poorly infectious for mammal hosts. But if you look at the mammal hosts that are getting infected with, perhaps, let's put aside the sea mammals for now, because it's a little unclear about those. But certainly the foxes, the bears, the mountain lions, you know, we think they're getting infected from sort of chomping on a dead or sick bird. So they're getting a huge amount of virus at one time. That's probably why they're getting infected. Little evidence, at least when there's wild population that is, and again, sea mammals aside, that there's any evidence that it's gone mammal to mammal. So these are one-off, we think, are one-off events where an animal's really had a huge amount of virus from sort of feeding on a sick or dead

24:35 Karen Waldrop carcass. And that's how they get infected. Similar to what we're seeing with hawks and birds of prey, eagles, and everything else too. Yes, exactly. But as far as it being different in mammals than birds, as far as the transmission and the ability to transmit, you see a lot of

24:50 Dr. Webby difference. Yeah, well, from the virus perspective, we get a little bit worried from when we see mammal infection, because if this virus is going to adapt to humans, it's much more likely that that adaptation is going to happen in an infection of a mammal. So while these viruses are circulating in birds, there's almost a selection against them being more mammalian-like. So that's why we get a little excited and probably why the meter sort of catches on to that excitement when we see mammal infections, that's the host. But right now, there's not a lot of evidence as to that. These mammalian infections have sort of caused much change in the virus. So clearly, it's a virus, still avian virus transmits well between avian species and can transmit from avian to mammal

25:36 Karen Waldrop in rare circumstances. But why would it, if it's working so well in birds, why would it adapt to transport humans? Exactly, and no mammal to mammal transmission. And so you've kind of talked, you don't think it's a lot of mink, like mammal to mammal, so that whole thing was in the mink

25:50 Dr. Webby to mammal, in the Spanish farm? Yeah, so that's, if we look, there's a, I guess. And I'm not sure how commonly known that is as far as that situation on that farm, as far as the mink to mink transmission. Yeah, so the mink to mink and the potential sea lions, some of the sea lions in Peru are situations where it's more likely there was mammal to mammal spread. I think the mink farm, they're still a little bit unclear. So apparently, some of the way they feed the mink is sort of just mass throwing out of meat into these cages. So there's still some possibility they were infected for a sort of common feed source, but I think probably a little bit of mammal to mammal transmission. We've actually just received that virus in our lab last week, so we're going to do

26:39 Karen Waldrop a little bit of work to see if it actually has any changes that might suggest transmission. A lot of our employees, but as well as also our members, they all have a lot of dogs, right? We waterfowl hunt and a lot of them have retrievers and other dogs and other pets too. So just, you know, there's been a lot of interest or concern among our members and as far as the susceptibility and transmission to domestic dogs. And didn't know if you could share a lot. We know

27:08 Dr. Webby we did have a dog, there was one mortality from a dog being infected. So didn't know if you could share a little bit more on that. Yeah, so we know dogs can be hosts of flu and they have actually had some lineages of flu that have been maintained within them, even here in the U.S. and some of the greyhound populations. But I think dogs right now, you've got to think of them a little bit like these others. Think of them like a fox or a skunk or a badger that's going to, if they feed on something and get a huge dose of virus, they can actually be infected with it. So the risk is still very low. I think they have to get a large amount of virus. From a duck hunter's perspective, you know, probably just retrieving a duck, the chances are probably pretty low. But if it was a dog in the backyard who came across maybe a dead carcass and was a little less trained and started tearing into it, so maybe then that's where the risk goes up. So yeah, low risk is not zero. But again, from a human health perspective, luckily we haven't seen that mammal to mammal spread. So there is a chance the dog probably has a higher risk than the owner. The owner's chance of catching it off their dog again is pretty slim. And again, another unsatisfactory answer. It's a low risk, but under the right conditions, we know it can happen. So pay attention to what you're doing. Absolutely. Yes, I think, yeah, it's any sort of respiratory symptoms in dogs. Absolutely. Just be a little bit more careful around them as well as sort of getting to a vet, but let the vet know in advance what might be

28:50 Mike Brasher happening. So at least they're a little bit better as well. And one of the primary reasons why we wanted to pick your brain on this is because I mentioned this a little bit earlier. If you go online and search for avian flu, human health risk, or something along that line, now you'll find articles where it talks about this being the potential next global pandemic. And so there's a lot of that sort of information out there right now. You can also find in those articles a very high apparent case mortality rate in humans for this virus as well as I think other H5 viruses over the life of their existence. That case fatality rate, if I'm remembering correctly, is somewhere around 50% is what's reported. But you'd probably be quick to clarify that we don't have a lot of confidence in that number. So if people were to have read any of those articles or heard about a high case fatality rate associated with this, provide some, I guess,

29:50 Dr. Webby comfort to us on why we shouldn't take that percentage to heart. Yeah, right. So one, we shouldn't take it to heart, but we should be at least a little bit concerned about it. But in terms of all influenza, that is high. But we've got to think about this particular virus. So as I said before, when any infectious disease, when anyone gets infected, there's going to be a sort of a gauntlet of disease severity. With H5s, again, the way they're typically picked up is people come into the hospital with severe disease. So flu is one of the differential diagnosis. They'll test them for flu. They'll see it's flu, but it won't type as one of the seasonal strains. And so then it'll go and get type for H5. We've got to think, so the only people that are probably getting diagnosed with H5, or most of them now, are those that are really, really sick. So people that have more mild disease, they go to a normal doctor's office, then they're not getting picked up. So yeah, when we talk about a case fatality rate, that's why they use that case fatality, because it's a case. In terms of how many true infections have been, probably a lot more. We've done some studies with collaborators in Egypt, where we've actually gone into some of their poultry raising areas and sort of bled people and looked for exposure. We can see the percentages up to sort of two, three, four, five percent of people can have evidence that they've been exposed to this virus, meaning likely infected. So yeah,

31:22 Mike Brasher the actual true number of cases is probably a lot higher than it is now. Somewhat related to that, the guidance from the CDC and other institutions out there now will advise that the risk to humans from this virus is still very low. Part of that, I think, is related to the fact that humans are not likely, the risk of humans coming into contact with the virus through contact with a bird is, for most people, pretty low. We were talking at lunch about this. The reason this question is really of interest to us and our members is that our waterfowl hunting members and a lot of other people that may interact with waterfowl, but especially hunters, are probably a group that are at higher risk of exposure to infected birds, dead birds, water that would have the virus in it. And so that's, we're sort of a special case of a subset of the human population. Are there certain ways that we could get exposed to that would be more concerning, that would be more likely to lead to severe virus? What are the areas we need to be most

32:34 Dr. Webby concerned about? Yeah, so there's another great question. So this particular virus, the fact there's been low number, relatively low number of human cases, yeah, there is some exposure. It's also a virologic property. Again, we talked before, this is still very much a bird virus. It has to make some changes to be a human virus. But you're dead right, people. It's a bit of a numbers game. So it's a very, very rare event. But the more chances you have of being exposed, that puts you at greater risk. So yeah, your sort of your audience is potentially at a higher risk. If we look at that, so one of the most risky events, and one thing we know about this virus is that it binds to receptors, what we call receptors. So this is on the cells of avian cells within sort of a bird, which are primarily in the gastrointestinal tract, a little bit in the respiratory tract. The virus is, the receptors that we have in our upper respiratory tract are a bit different. So that's why the virus doesn't bind so well to our nose. We do have some of those same receptors deeper into our lungs. So the thought is that any activity that produces more of an aerosol sort of is more a dangerous activity than perhaps just collecting a duck or from a, you know, from a retrieved duck or something like that. So I think anything that you could do that would be sort of allowing that virus to sort of pillow and sort of into the air where they're plucking, those are the types of things that are more at risk. And some of the nice studies have been done, you know, both here in Southeast poultry and confined settings, or in some of the poultry markets in Asia as well, looking at where the most risk is. And it tends to be in those situations where they're doing sort of de-plucking. So these de-plucking machines that spin the bird around and can create aerosols. So again, thinking about risk to hunters or people cleaning ducks, anything you do that again would sort of allow the virus to sort of

34:38 Mike Brasher be aerosolized, that's the most risk. So that's where you should take the most care for sure. I believe Dr. Dave Stalnick echoed the same sentiment and he was advising that individuals that are plucking their birds certainly through those mechanical pluckers, make sure you're in a well ventilated space. It wouldn't be out of the question. He would advise

34:58 Dr. Webby if you are in that situation, consider wearing a mask in that particular situation, you would agree? Yeah, no, absolutely. There's some really, I don't know how much, I've already wasted a lot of time. Some really nice studies where Southeast poultry, you were talking about where they sort of mimic these environments, they sort of mimic the live poultry market with de-feathering machines and they put ferrets at different places around this. Ferrets are the host that we use to sort of mimic human infection and they found they sort of mimic from purchasing a bird to killing it. And it was, it was when that de-feathering machine was in action, that's when the ferrets around it became infected and the same, they've had the air sampling things they've taken into some of these markets

35:38 Karen Waldrop and it's definitely the de-feathering is where a lot of the virus gets spilled into the air. So for this virus maybe to become highly infectious for humans, you mentioned just a few minutes ago that the virus would have to make some changes, right? And so we talk about viruses mutating and things like that, but what does that really mean and what do we currently know about the risk of it mutating to where it would become highly infectious for humans? And you talked a little bit about that when we talked about the mammal to mammal transmission in birds,

36:08 Dr. Webby if you could expand on that. Yeah, so the flu is sort of again one of these viruses that continually mutate, so it keeps on throwing out mutations every time it replicates. And we know from studies that were done in the lab that for this virus, the H5 and probably others too, to change from being a bird virus to a human virus, there has to make almost what we saw three categories of changes. And what I mean change, I mean mutations in the various proteins that it makes. One of them we've already talked a little bit about is that it has to change the ability to bind from that receptor on the avian cell to the receptor in the upper respiratory tract of human cells. That probably takes two or three changes in one protein to do that, the H5 protein itself. We haven't seen much evidence that this virus has much capacity to easily make those changes. There's another one in the replication machinery of the virus that when it gets into a cell that makes more copies of itself, we know there's a mutation or a series of mutations that if a virus gets it, it replicates a bit better in mammal cells. We've seen that mutation quite a number of times when these mammals have been infected. So that mutation is not in birds, but again in the foxes, the raccoons, the bears, we do see those changes quite a bit. So that's a change this virus can make pretty easy. And the other one again is a little bit more to do with sort of stability of this virus and sort of the nitty-gritty of pHs within different cells. I don't know if we have to get into it, it kind of has to make those changes as well. We don't know as much about those. So three categories of changes. One we know this virus can do easily. One we know it's hard. The other we're a little uncertain about. But I think that's sort of the coming back to the point is why we get really worried about mammal species. While this virus is replicating in birds, it's still what's making mutations and stuff, but there's no pressure or selection in those birds for that virus to make the change. There's almost a pressure against a change because if these viruses make those mutations that make it more mammalian-like, it makes it less avian-like. And if you're a virus that wants to replicate and spread an avian, you don't want to make those changes. So it's a good host. Yeah, it's a good host. So I'm thinking of why we worry when it gets into a mammalian host because that's the host that's going to put a little bit more pressure

38:32 Mike Brasher on that virus to actually make those changes. I hope that made sense. This is probably a good time to check in to see if there are questions from anybody online, Chris, or anybody here in

38:42 Dr. Webby the audience. We have a few others and I have Bobby here. Hey, my question is, so it spreads during the de-feathering. Is that because of dander or bloodborne? Yeah, probably a little bit of it. So these highly pathogenic, which this H5 is, they go systemic. So there's probably a bit of viremia. You can get some in different parts of the… So it's probably from blood, but there's a little bit of dander as well. But even just the virus itself from whatever secretions, it's just getting sort of… People have found… I think the risk is low, but even from meat, you can… Juices from meat, you can find virus sometimes. So it does get in throughout these birds. And so it's probably a little… Those environments are typically not the cleanest. So there's a lot of different bits and insides that are also in that mix.

39:44 Mike Brasher Following up on that, I've wondered about the ability of the virus to be aerosolized to get on the feathers as a result of… To be in the water and then water, of course, on the feathers for duck or goose, it's in the water. Could those water droplets be aerosolized to a point that they could be inhaled more deeply as a result of the plucking process? Whenever I've thought about that elevated risk in those plucking situations, that's one of the things that I've thought about.

40:17 Dr. Webby Because you know the virus is in the water in these areas where we're seeing sick or dead birds. Is that a real concern? Yes, theoretically, yes. I think what would give me a little more assurance in that area is, again, I think for a mammal to be infected with this virus, when you have to be dang lucky, but you also have to get a high dose. And so the question would be, would there be enough concentration of virus in water that would get on that animal that would be enough to infect? And I don't. To me, my gut feeling is you need a little bit more virus than just sort of what's on the surface from contamination from water. But that's a lot of

41:05 Audience this hand waving. So this is just kind of building off of what they were just talking about, but would avian researchers that work with things like air boats and stuff that push off a whole lot of aerosolized water, should they be more careful in the coming field seasons? Not standing behind the

41:20 Dr. Webby airboat? Yeah, again, it's anything that increases risk. It increases risk. Again, it comes back to that thing that would that contaminated water have enough sort of infectious dose to infect you? I would maybe not. Had it just gone over where a huge amount of birds had just been, where there's a lot of infection going on, I guess it's possible. But again, I think the dose on that is probably

41:52 Audience not going to be high enough. Question from… This question's online from William Bond. The name of this strain that's been used is highly pathogenic avian flu. Is there a significant pressure on strains like this to become less pathogenic over time as that behavior is more likely for an infection to last longer and infect more birds, potentially allowing this virus to still circulate

42:16 Dr. Webby but not be much of concern due to lower mortality? Yeah, so great question. So William, I think the answer… So highly pathogenic in the flu world, again, I apologize if you guys have heard this a thousand times before, but so most we talked about before in these wild bird populations, the H1 through H16 subtypes of flu, those are in this low pathogenic form. Subtypes from the H5 or H7, when they get… That doesn't happen, we don't think it happens in waterfowl. It happens when they get into terrestrial poultry species, so into chickens, turkeys, maybe quail. Some of those H5 and H7 types of virus, through a molecular mechanism we know, they gain basically extra amino acids in one part of the protein, and that actually allows them to go systemic. We talked about systemic spread before. It's that transition, this gain of extra amino acids that allows them to actually spread systemically, and that's what causes this transition from a typical low pathogenic form to a high pathogenic form. I'm pretty confident in saying we've seen this happen a number of times. It doesn't happen often, but we've seen it happen. We've seen H7 outbreaks even in Tennessee, for example, over the last decade or so. I don't think we've seen it where these viruses lose those amino acids. If you're speaking of a virologic property, I don't think we've seen it where it goes from high pathogenic to low pathogenic. But I think what's more likely to cause that virus to go a little bit less is perhaps that host immunity. This particular virus, the H5, the highly pathogenic H5, again, these descend all from that goose virus, well, probably even before that, but we first saw it in goose virus in 1996. We've seen waves of different forms of this virus. Sometimes they're a little more nasty than others, but this virus now is the same as that. It's been circulating for 20, 25 years and hasn't really lost a lot of its intrinsic pathogenicity. The hope that this thing will do go from killing everything to killing nothing I don't think is likely now. Do you know if there's any potential role or prospects for vaccine either in poultry or humans, anything like that? Yeah, so there's actually, in terms of both sides of it, if you talk about the human, they have actually done clinical trials with H5 vaccines. So back in Hong Kong in 1997, where 18 infected, 16, that actually triggered a number of clinical trials with H5 vaccines. We have a little bit of vaccine that the US government has even prepared and done some clinical trials with that. We've actually looked at the blood from some of these people in the lab at St. Junot. It does actually recognize these viruses pretty well. So from a human health perspective, we do know how to make vaccines against it. There isn't huge amounts of them, but that could be ran up pretty quickly. From a poultry perspective, many parts of the world have been vaccinated against H5. Think China, think Egypt, think Mexico, or Mexico for not this virus, but other viruses. Other countries have been vaccinated against this as well. From a US perspective, I think it comes down to, it really boils down to, at least for poultry trade, there's dollars. And a lot of important countries will use an inability to prove that you're free of disease, which vaccination makes that harder. But having said that, I think we're about to, from what I understand, about to vaccinate some condors in California here in the very, very near future. So some populations, we're going to see vaccination on a broader scale. In poultry, I think it's a little more questionable, and we just don't have a good way to vaccinate wild birds, unfortunately. And I think vaccinating poultry, even in talking as many birds might be in one facility, the difficulty in doing that as well. Yeah, no, it's a little bit from, you know, some of these, there's millions and millions of birds. So, how do you, if you wanted to vaccinate all the poultry in the US tomorrow, that's, yeah, that's going to take many, many months. So that's a controlled environment. I can't imagine wild population being able to do that. Yeah. And unfortunately, most of the vaccines we have, whether it be for humans or for birds as well, is sort of an injection type device. We don't have a good way to spray vaccine for these yet, although people are working on those. So it's a much,

47:05 Mike Brasher yeah, those wild birds are going to be tough. They're going to be tough. I have a couple of final questions. We have a lot of staff that interface with waterfowl hunters. The group that is going to be, that's going to have certainly a keen interest in this, going to be exposed to the situations where they're going to encounter this more often. If our staff are asked by waterfowl hunters, hey, I hear about this avian influenza virus. Do we expect it to be around again this year? I think we know what the answer to that's going to be. But how concerned do I need to be about it? What advice would you give to our members to, for a brief statement, well-informed statement about what they need to be communicating to

47:45 Dr. Webby waterfowl hunters? Yeah, so I think that statement will be that the risk, this is still a low risk virus for human health, but it is not zero. So I think the more that those hunters can be aware that this virus is there, aware of the fact that there is a risk even if low. So anything they can do to, this is not, I clearly haven't given you a short answer for your people to give, but anything they can do to reduce that risk is a great idea. And so just in their mind, think about that duck is potentially infected. So what can I do, whether it be gloves, just being more careful when you're de-feathering, et cetera. Anything you can do to reduce the risk is good. So just think a little bit more about that, sort of that bird as being a source of infection for you. And the same sort of

48:36 Mike Brasher COVID-like thing, washing your hands and stopping as much as you can, any sort of inhalation. Same type of guidance regarding their dogs. Keep an eye on them if they appear ill. Be aware of their potential exposure to sick birds. Don't be afraid to contact your vet if you think something

48:56 Dr. Webby is maybe in this. That's right. But yeah, so I think as we did before, I think definitely if you suspect it could be, then give the vet a little bit of a heads up because they may not want that bird sort of bowling into their front office. So they may look at it some other way. We have another question from the audience. Did I say bird or dog? If I said bird.

49:15 Karen Waldrop Oh, I did. Go ahead. We know what you meant.

49:18 Audience Where are the condors that might be vaccinated or zoos vaccinated?

49:22 Dr. Webby So some of the things, yeah, so the condors, I believe, are some of the populations are the California condors. So I was on a call with some folks yesterday who mentioned I think they're about to initiate that. And also I think this will now also spread to some of the more valuable zoo populations as well. So we do have avian vaccines that work against this virus, actually quite a number of different platforms. So yeah, I think we'll see more of some of these more valuable populations. Zoo birds will start to be vaccinated. But because they're endangered condor, California condors, one they're going to try to… Yeah. And that's exactly. I think there's a lot of condors. Again, I'm by no means a condor expert. You guys probably more than me.

50:00 Mike Brasher Big concern. Yeah. Any final questions from the audience? Yes.

50:05 Audience In light of your understanding that this isn't going away anytime soon, do you consider some of the regulations, cautions out there to be reasonable to expect as the new normal?

50:17 Dr. Webby I think so. I think we've been so lucky as a continent or continents over the past 25 years not have this virus before. Unfortunately, we've joined the group now of the rest of the world with the parts of my old home territory. Australia, New Zealand's probably the only place they don't have it now. So yeah, I think, again, don't get me wrong. I don't know for certain that this virus is not going to go away. Most people who talk to you

50:45 Karen Waldrop suggest it's not, but I think it's very normal. I wonder if the question meant from regulations. I wonder if that was from a hunter harvest question coming in from Canada to the US. Last year there was the ban. I think that might have been more along the lines of the question

51:01 Dr. Webby as far as those regulations. I see. But they make no sense. But even from our environment, there's a lot of things that don't make sense regulation-wise. Even up until for us as a lab, we're importing samples from Canada, we have to potentially age five infected. We have to treat them differently, whereas this virus is everywhere. So then in that case, then the regulations I hope would change because this is much more likely to be everywhere and those sort of border things

51:34 Mike Brasher make no sense at all. We've received that question from a number of staff already. Do we have any insight on what those import restrictions are going to be this year? We don't know yet, and we're efforting some conversations with USDA AFIS to try to get some clarity and offer some additional suggestions. So I offer that for our staff that may be wondering kind of where we as an organization

51:56 Audience stand in that regard. So, efforting. We have another question. A person could clearly tell when a Canada goose was infected by behavior and cloudy eyes, some folks were still eating these birds,

52:08 Dr. Webby just making sure they were well cooked. Is this an acceptable practice? So I guess it comes back to, again, it's a low chance of being infected, but anything you do to increase that chance increases. The chance is right. So is it advisable to eat something you think is a good chance of being infected with H5? No, not really. But at the same time, we haven't seen people infected via that route. But yes, it's not a good practice. For example, we work with these viruses in the lab. We sort of do the full sort of spacesuit with a respirator on if we're dealing with infected animals with this particular virus. So I don't suggest you all go and do that. But eating them, if you can get away with it, is probably not a good idea. Any sick or dying wildlife that we consume is probably not a good practice. I think the same thing, going back to sort of the mammal, again, we've got to even think at psyche a little bit if this is going to be endemic. If there is some of these birds of prey or mammals that are acting a little bit weird, we should be a little bit careful around them and think that potentially is a source of infection for me. Before we go there, any final questions from Karen? No, I don't think so. Thank you. We have one final question from the audience. Dr. Mike has mentioned that you are part of the barbecue circuit. So would you enlighten us on your barbecue prowess? I can't. It was a secret. I'm in the circuit too, so I understand. Yeah, no. So we did compete in the Memphis Amai barbecue. We actually did pretty well this year, but that's a rarity. Typically,

53:58 Mike Brasher we're closer to the bottom than we are at the top. How did you get on? We finished 18th out of 79, but we won Turkey and we won vinegar sauce. Oh, yeah, very good. Congratulations. Maybe I need your secrets here. So if there are no other questions, I'll just say thank you. Dr. Webby, thank you so much for your time. Thanks for joining us earlier for lunch. It was a great conversation. Karen,

54:29 Dr. Webby thank you again for being part of this. And I'm happy if people have questions they think of later, if they could, you know, my email is richard.webby.stjude.org or if they want to follow them through, happy to answer. So thank you. Thanks everybody for joining us.