Examining the Risks of Bird Flu
BROOKE GLADSTONE This is On the Media, I'm Brooke Gladstone. We end on a disaster yet to come, and how salvation is likely to slip through our hands. It's no secret that after the past year, prices for the basics have gone up. But one staple stood out.
KTLA5 According to the latest stats that are out there. Egg prices in January were up by 70% from a year before.
BROOKE GLADSTONE Sure, record inflation played a role, but that's subsided. No, something else is afoul.
WBIR WRA says in the last year, the poultry industry had to euthanize millions of turkeys in chickens nationwide because of the bird flu.
BROOKE GLADSTONE A strain of bird flu known as H5N1 has led to what some call the largest avian influenza outbreak in U.S. history. Of course, birds catching a deadly bird flu seems kind of unsurprising. But in Spain, there was also an outbreak of H5N1 at a mink farm. That's scary. And not just for minks. Their respiratory tracks are far more similar to ours. Leading to a perplexing question for public health officials. Is H5N1 evolving the airborne ability to infect mammals en masse.
KEREN LANDMAN Now, that is still hypothetical.
BROOKE GLADSTONE Keren Landman covers public health, infectious diseases and the health workforce at Vox.
KEREN LANDMAN It's not clear from the publication that detailed this particular outbreak that the minks did transmit the virus to each other. It's possible that all of them became infected by eating the same infected bird or even by transmitting flu to each other through their feces. It's not totally clear that this virus in that population has acquired the ability to be transmitted through the air, which would be a much more concerning development.
BROOKE GLADSTONE It's also gotten in other animals grizzly bears in Montana – skunks. Can humans catch bird flu now?
KEREN LANDMAN Yes, but I want to clarify that. Humans can catch bird flu through very close contact with highly infected birds not casually walking by a backyard chicken. We are talking about usually poultry workers or people who work in markets where these animals are present in really high quantities and when there's not a lot of ventilation.
BROOKE GLADSTONE So we're very unlikely to catch it, but it's pretty deadly if we do. According to data from the World Health Organization, last month, between January 2003 to November 2022, there have been 868 cases of human infection reported from 21 countries, of which 457 were fatal. More than half. Comparing that to COVID 19, according to Johns Hopkins. The highest recorded mortality rate in the world was just under 5% in Peru. It was just a little over 1% here. More than half.
KEREN LANDMAN I don't mean to downplay the disease's case fatality rate, but a lot of these infections are taking place in countries that have a different standard of medical care than in the United States. That can certainly impact the fatality rate of these infections. That's not to say that we shouldn't be concerned about this. If, God forbid, an H5N1 were to acquire the ability to spread through the air among humans, it would spread in countries with different standards of medical care than in the United States.
BROOKE GLADSTONE You write, If there's anything concerning about the current bird flu, it's that it could mutate and evolve. Right. I mean, thanks to COVID 19, most of us are familiar with the havoc that variants can bring. If the bird flu evolves, how prepared are we?
KEREN LANDMAN Oh, boy. Do you want to talk first about how bird flu evolves or if you want to talk about preparedness?
BROOKE GLADSTONE Start with column A.
KEREN LANDMAN Well, bird flu and flu viruses in general are great at evolving. I mean, if you think that coronavirus is good at spitting out a new variant every few months, you ain't seen nothing. Influenza is the O.G. Shapeshifter. Different from the way viruses and other families mutate.
BROOKE GLADSTONE Such as coronavirus.
KEREN LANDMAN So they're in a totally different family of viruses. And scientists have a way of talking about the way influenza viruses mutate. That's simplified. There are two different ways that it changes. One is called 'drift', and one is called 'shift.' All viruses replicate themselves billions of times over, and as they're doing this, they make lots of little errors. And sometimes those errors really add up to translate into a way of behaving that can change the way the virus causes disease, the severity of disease, the way it spreads. However, they take a long time to take place and they usually don't result in an immunologically novel virus. Right.
BROOKE GLADSTONE So what's the difference between the way bird flu mutates and coronavirus?
KEREN LANDMAN So coronavirus can also do drift type mutation. It can also. Make lots of errors as it replicates itself and make lots of changes that make it look like a new variant, for example, that does change. But influenza virus has this added ability of being able to basically swap an entire chunk of its genome with another strain of flu virus that it meets in a cell. That kind of change is called shift. It's almost like if you had a set of eight cards because influenza viruses have eight segments of their genome and you wholesale traded one of those cards with another person, I think your producer earlier called it Virologic Go Fish. And it's a major change. It can give it not only new abilities very, very quickly, but it can also make it look very novel, very quickly to our immune systems. So not a whole lot of other viruses do this kind of shift. And that is why influenza virus has proven itself to be so good at causing pandemics, because as it sort of moves through populations, it can start acquiring new characteristics very quickly. It especially does this well when it is in an animal with another virus that's very different. And both viruses have lots of opportunities to replicate. But not all animals are hospitable to that kind of replication. Birds are great at being infected by H5N1. We're great at being infected by non avian flu type viruses.
BROOKE GLADSTONE Got it.
KEREN LANDMAN But there are mixing vessel animals that are great at being infected by both. Minks are among them. And so when those kinds of animals get infected by multiple types of flu strains at the same time, that's an opportunity for those flu strains to engage in 'shift type' mutations that very quickly allow them to acquire new genetic characteristics that can really change the way they behave and transmit. And that's what makes transmission in this kind of a mammal especially concerning.
BROOKE GLADSTONE Now let's move on to preparation, specifically vaccines. Zeynep Tufekci wrote in The New York Times that, quote, All but one of the approved vaccines for this are produced by incubating each dose in an egg.
KEREN LANDMAN And she also mentions a couple of paragraphs down from there that mRNA based platforms, which do not depend on eggs and which we used to create most of the coronavirus vaccines that we've used in this country. There seems to be a fair bit of confidence among the folks I've talked to that we would be able to use an mRNA platform to develop a vaccine to target a novel flu virus pretty rapidly, and we'd be able to scale that up. The question is whether people would take it. And as we've seen, that is much, much more complicated.
BROOKE GLADSTONE But is the public health infrastructure really there? I guess the bigger question is, did we learn any lessons in the last several years?
KEREN LANDMAN Well, not only is this an issue of funding, although public health at the federal, state and local level is really not funded to the degree that we need it to be to be prepared. But also there are big issues of morale and public health personnel leaving the profession for the private sector. We also have, unfortunately in this country, restricted the kind of research that would really help us know what kind of mutations are worrisome and what are not. And this is vein of function research, the kind of research that allows experts to tinker with a flu virus in the lab, give it the characteristics that worry us, and then see if it actually causes disease in an animal model. We're not allowed to do those kinds of research anymore in the U.S., funded by the the NIH, which is the most important source of scientific research funding in this country, doesn't fund that research anymore. They put it on hold in 2014.
BROOKE GLADSTONE Because people don't like unnatural, man made things being created in the world.
KEREN LANDMAN Yeah, there's a lot of worry that doing this kind of work is itself a big risk to humanity's health, and that's prevented a lot of really important research from happening.
BROOKE GLADSTONE Here's a funny question. Shouldn't we be vaccinating the chickens.
KEREN LANDMAN So they actually are good vaccines for chickens? However, it is hard for people to tell whether a chicken that has antibodies to the flu has those antibodies because it got infected or because it got vaccinated. When countries determine whether they want to accept our exports, if our egg populations or our chicken populations have these antibodies that could actually prevent them from taking those exports because of concerns that they may be receiving infected eggs or infected chickens into their countries.
BROOKE GLADSTONE Your Vox colleague Kenny Torella says we should blame the DIVA problem.
KEREN LANDMAN DIVA short for differentiating infected from vaccinated animals. And that's exactly the challenge here, although we want to protect our own flocks in the United States in our own eggs. Doing so could actually signal to other countries not that we're protecting them, but that they are infected. And that is a really unfortunate problem.
BROOKE GLADSTONE Tirella said that that means the big poultry exporters like the U.S., which sends 18% of its poultry abroad, don't vaccinate because they don't want to miss out on international trade.
KEREN LANDMAN Isn't that crazy? Instead, we'd rather just kill tens of millions of animals in awful ways.
BROOKE GLADSTONE Everybody who studies this probably has a different level of worry. What's yours?
KEREN LANDMAN This incursion into this population of minks is itself not a three alarm fire to me. There's a lot that needs to happen for those viruses to become agents of a human pandemic. The way to avoid this is by really prioritizing the things that we need to do to find and respond to these changes when they happen, and also to know when these changes really matter. So that means reconsidering the importance of gain of function research, also funding surveillance activities. So these are monitoring activities that let public health people know what kinds of flu viruses are circulating in farmed animal populations, wild animal populations, and in humans – quickly figure out what is going on and where so they can respond appropriately and then funding those response activities. You know, we've just really underfunded and under supported our public health infrastructure, not only in the United States, but worldwide. And even though the pandemic showed us just how much that is to our detriment, it doesn't really seem like we've gotten the message. I mean, funding public health didn't come up at all in the State of the Union speech this year. I was sort of shocked because, you know, this really feels like a moment where if we don't respond to the threats that we know are out there, we are going to be in some big trouble in the future. And flu could very easily be the agent of the next pandemic.
BROOKE GLADSTONE It sounds like the scariest thing isn't H5N1 or any other flu. It's us grabbing the attention of our elected officials and our population. It may be a very slow moving train, but we still have to deal with it.
KEREN LANDMAN That's right. This time it looks like the influenza virus that affected these minks didn't take all the steps it needed. But if we as a humanity don't develop a sense of respect for these pathogens and respect for each other, that would provoke us to do what we need to do. I mean, do you have faith that everybody, you know is going to put masks back on and go back to social distancing if we need to do this out of concern for a new respiratory pathogen? Do we have faith that everyone in our neighborhoods is going to run and get the new vaccine that's produced? Should we see a new pandemic potential flu virus emerge? Those are questions I wouldn't have imagined doubting the answer to a few short years ago. But having seen the way the coronavirus pandemic unfolded, I'm not sure that we really have it together to respond collectively. If a flu virus does take the steps it would need to take to really cause another pandemic.
BROOKE GLADSTONE Keren, thank you very much.
KEREN LANDMAN Thanks so much for having me.
BROOKE GLADSTONE Keren Landman covers public health at Vox.
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