Post by Nadica (She/Her) on Oct 17, 2024 0:49:04 GMT
Is it time to freak out about bird flu? - Published Oct 16, 2024
By Helen Branswell
If you’re aware of the H5N1 bird flu outbreak in U.S. dairy cattle — you may have seen some headlines or read something on social media — perhaps you are wondering what the fuss is about. Yes, there have been a couple dozen human cases, but all have had mild symptoms. The virus does not decimate herds in the way it does poultry flock; most — though not all — of the infected cows come through the illness OK.
If, however, you are more familiar with the history of this form of bird flu, you might be getting anxious. You might be worried that no one has figured out how one of the infected individuals, who lives in Missouri, contracted H5N1. Or you might recall that the virus has killed half of the 900-plus people known to have been infected with it over the past 27 years. Above all, you might fret that the virus is now circulating in thousands of cows in the U.S., exposing itself to some unknowable portion of the more than 100,000 dairy farmworkers in this country — the consequences of which could be, well, disastrous.
Ongoing transmission in cattle means that every day in this country, a virus that is genetically suited to infecting wild birds is being given the opportunity to morph into one that can easily infect mammals. One of these spins of the genetic roulette wheel could result in a version of H5N1 that has a skill that is very much not in our interest to have it gain — the capacity to spread from person to person like seasonal flu viruses do.
So is this freak-out time? Or is the fact that this virus still hasn’t cracked the code for easy access to human respiratory systems a sign that it may not have what it takes to do so?
The answer, I’m afraid, is not comforting. Science currently has no way of knowing all the changes H5N1 would need to undergo to trigger a pandemic, or whether it is capable of making that leap. (This important article lays out what has been learned so far about some of the mutations H5N1 would have to acquire.)
The truth is, when it comes to this virus, we’re in scientific limbo.
Communicating about the threat that H5N1 poses is extraordinarily difficult, as the varying tones of the media coverage of the bird-flu-in-cows situation may have conveyed. Some of the experts quoted in some of the reports are clearly on edge. Others are uncertain; some seem keen to play down the situation.
Since the outbreak was first detected in late March, the Centers for Disease Control and Prevention has declared, over and over again, that it deems the risk to people who aren’t working with cows to be low. The troika of United Nations agencies that monitor H5N1 closely — the World Health Organization, the World Organization for Animal Health, and the Food and Agriculture Organization — shares that opinion.
Between the lines of both assessments, though, are words public health authorities rarely volunteer but will acknowledge if pushed. As best they can tell, the risk now is low. But things could change, and if they do, the time it takes to transition from low risk to high risk may be dizzyingly brief.
We’ve seen this type of phenomenon before. In February 2020, on the very day the WHO announced it had chosen a name for the new disease that was spreading from China — Covid-19 — senior U.S. officials speaking on a Washington panel organized by the Aspen Institute were describing the risk of spread in the U.S. as “relatively low.” Two weeks to the day later, one of those people — Nancy Messonnier, then a high-ranking CDC official — disclosed during a press conference that she’d warned her children over breakfast that morning that life was about to be upended.
Messonnier, who was silenced by the Trump administration for her candor, was correct. By mid–March, schools were closing, many workers were transitioning to working from home, and ambulance sirens began haunting New Yorkers as the city’s hospitals started to overflow.
One of the fundamental reasons it’s difficult to clearly communicate the risks posed by a flu virus is that it is impossible to predict what influenza will do. There’s a line that flu scientists use to describe the dilemma; I first heard it from Nancy Cox, the former head of the CDC’s influenza division, who retired in 2014. “If you’ve seen one flu season, you’ve seen one flu season.”
To be fair, there are a few basic truisms of flu. There will be a surge of flu activity most years; the first winter of the Covid pandemic was a rare exception. People will get sick — some mildly, some miserably. Some will die. The virus will evolve to evade our immunity and force the regular updating of flu vaccines. Because the viruses don’t give us roadmaps of where they’re heading, some years vaccines will work reasonably well, others not so much. And finally, there will be more flu pandemics.
But when? No one knows. Will they be deadly? The 1918 Spanish flu was far worse than the Covid pandemic, but some bad flu seasons claim more lives than the 2009 H1N1 pandemic did. Will H5N1 become a pandemic virus? Anyone who insists it is inevitable is guessing. Anyone who opines that it will never happen is guessing, too.
Glen Nowak spent 14 years in communications at the CDC; he was director of media relations for the agency from 2006 to 2012, a period that included the H1N1 pandemic. Nowak, who is now a professor of health and risk communications at the University of Georgia, says communications about anything flu-related should start by leaning into the unknowable nature of flu.
“Flu viruses are very unpredictable and we don’t have a crystal ball to tell us how any flu virus is going to play out, whether it’s a seasonal flu virus, an avian flu virus. We just don’t know,” he said when we spoke recently about the challenges of H5N1 communications. “I think you always want to have that at the forefront versus trying to convey more certainty as a way to reduce or alleviate concern.”
Because I cover infectious diseases outbreaks — and covered H5N1’s twists and turns obsessively for a number of years — I have on occasion been accused of inciting panic or hyping threats that don’t materialize. (I would argue I’m just doing my job.) I remember in the early days of 2020, when experts were divided about what was going to happen with the new coronavirus, someone who had mocked me from time to time over the years on Twitter — X was still Twitter then — popped into my feed to ridicule me for making a mountain out of a molehill.
Covid was no molehill. But I am sensitive to the fact that not every looming outbreak will take off and that Covid-level events are blessedly rare. Public health officials know this, too. They tend to shy from calling the code, as epidemiologist Caitlin Rivers of Johns Hopkins’ Bloomberg School of Public Health wrote in her new book, “Crisis Averted.” (I reviewed it here.) I think that fear of being seen to be crying wolf may have caused public health officials to downplay the risk of Covid for too long in 2020. Paradoxically, the toxic hangover of the pandemic may make them even more reluctant to warn people of future disease threats.
So how should one talk about the risk H5N1 in cows poses? Nowak, who is on a National Academy of Sciences, Engineering and Medicine committee reviewing the CDC’s Covid-19 vaccine safety research and communications, said it depends on who you’re communicating to, and what you expect them to do with the information.
“You always want to know: Who are the priority audiences? Who really needs to have information about what we need to be doing to prepare for this?” he said, suggesting that right now the answer is probably policymakers facing decisions about how to prepare for the possibility of wider spread, farmworkers who need to be protected against the virus, and local public health officials on the lookout for human cases. It’s probably not people in general, Nowak said.
“You can’t really FYI the American public. We can FYI our friends but when you FYI the public and you’re a government agency like CDC or FDA … people are rightly going to say: Why are you telling me that? … What should I do with it?” he said. “You can’t simply say: ‘I just thought you ought to know.’”
With some exceptions — flu researchers, people who keep abreast of infectious disease science, and of course you, faithful readers — this outbreak probably isn’t hitting the radar of the average individual, Nowak said. “My assumption is that a lot of the messaging that is coming out of CDC is probably invisible to the public.”
I’ve been covering H5N1 since early 2004 and I’ve done plenty of worrying about it over the intervening years. But having followed it for so long, I no longer assume every unwelcome thing the virus does means we’re on the precipice of a pandemic. Still, I have never felt that this virus is something I can safely cross off my things-to-watch-closely list.
So I have no answer for the question: How much worrying should we be doing about H5N1 right now? But I take some solace from the fact that flu experts don’t either.
The world’s leading flu scientists recently met in Brisbane, Australia, for a key flu conference that is held once every two years, Options for the Control of Influenza. As you might expect, there was a lot of discussion — some on the program, some in the hallways — of the H5N1 outbreak in U.S. dairy cattle. But even there, among the best minds on influenza in the world, there was no clarity about the risk the situation poses, said Malik Peiris, chair of virology at the University of Hong Kong’s School of Public Health.
Peiris has been studying this virus since it first triggered human infections in 1997 in Hong Kong. He has a very healthy respect for its disruptive capacities. No one Peiris heard or spoke to suggested that H5N1 could never gain the ability to transmit easily from person-to-person. But likewise, no one appeared confident that widespread human-to-human transmission of this virus is inevitable or even highly likely, he said.
There was agreement, however, around at least one notion: Letting this virus continue to spread unchecked in cows is profoundly unwise.
By Helen Branswell
If you’re aware of the H5N1 bird flu outbreak in U.S. dairy cattle — you may have seen some headlines or read something on social media — perhaps you are wondering what the fuss is about. Yes, there have been a couple dozen human cases, but all have had mild symptoms. The virus does not decimate herds in the way it does poultry flock; most — though not all — of the infected cows come through the illness OK.
If, however, you are more familiar with the history of this form of bird flu, you might be getting anxious. You might be worried that no one has figured out how one of the infected individuals, who lives in Missouri, contracted H5N1. Or you might recall that the virus has killed half of the 900-plus people known to have been infected with it over the past 27 years. Above all, you might fret that the virus is now circulating in thousands of cows in the U.S., exposing itself to some unknowable portion of the more than 100,000 dairy farmworkers in this country — the consequences of which could be, well, disastrous.
Ongoing transmission in cattle means that every day in this country, a virus that is genetically suited to infecting wild birds is being given the opportunity to morph into one that can easily infect mammals. One of these spins of the genetic roulette wheel could result in a version of H5N1 that has a skill that is very much not in our interest to have it gain — the capacity to spread from person to person like seasonal flu viruses do.
So is this freak-out time? Or is the fact that this virus still hasn’t cracked the code for easy access to human respiratory systems a sign that it may not have what it takes to do so?
The answer, I’m afraid, is not comforting. Science currently has no way of knowing all the changes H5N1 would need to undergo to trigger a pandemic, or whether it is capable of making that leap. (This important article lays out what has been learned so far about some of the mutations H5N1 would have to acquire.)
The truth is, when it comes to this virus, we’re in scientific limbo.
Communicating about the threat that H5N1 poses is extraordinarily difficult, as the varying tones of the media coverage of the bird-flu-in-cows situation may have conveyed. Some of the experts quoted in some of the reports are clearly on edge. Others are uncertain; some seem keen to play down the situation.
Since the outbreak was first detected in late March, the Centers for Disease Control and Prevention has declared, over and over again, that it deems the risk to people who aren’t working with cows to be low. The troika of United Nations agencies that monitor H5N1 closely — the World Health Organization, the World Organization for Animal Health, and the Food and Agriculture Organization — shares that opinion.
Between the lines of both assessments, though, are words public health authorities rarely volunteer but will acknowledge if pushed. As best they can tell, the risk now is low. But things could change, and if they do, the time it takes to transition from low risk to high risk may be dizzyingly brief.
We’ve seen this type of phenomenon before. In February 2020, on the very day the WHO announced it had chosen a name for the new disease that was spreading from China — Covid-19 — senior U.S. officials speaking on a Washington panel organized by the Aspen Institute were describing the risk of spread in the U.S. as “relatively low.” Two weeks to the day later, one of those people — Nancy Messonnier, then a high-ranking CDC official — disclosed during a press conference that she’d warned her children over breakfast that morning that life was about to be upended.
Messonnier, who was silenced by the Trump administration for her candor, was correct. By mid–March, schools were closing, many workers were transitioning to working from home, and ambulance sirens began haunting New Yorkers as the city’s hospitals started to overflow.
One of the fundamental reasons it’s difficult to clearly communicate the risks posed by a flu virus is that it is impossible to predict what influenza will do. There’s a line that flu scientists use to describe the dilemma; I first heard it from Nancy Cox, the former head of the CDC’s influenza division, who retired in 2014. “If you’ve seen one flu season, you’ve seen one flu season.”
To be fair, there are a few basic truisms of flu. There will be a surge of flu activity most years; the first winter of the Covid pandemic was a rare exception. People will get sick — some mildly, some miserably. Some will die. The virus will evolve to evade our immunity and force the regular updating of flu vaccines. Because the viruses don’t give us roadmaps of where they’re heading, some years vaccines will work reasonably well, others not so much. And finally, there will be more flu pandemics.
But when? No one knows. Will they be deadly? The 1918 Spanish flu was far worse than the Covid pandemic, but some bad flu seasons claim more lives than the 2009 H1N1 pandemic did. Will H5N1 become a pandemic virus? Anyone who insists it is inevitable is guessing. Anyone who opines that it will never happen is guessing, too.
Glen Nowak spent 14 years in communications at the CDC; he was director of media relations for the agency from 2006 to 2012, a period that included the H1N1 pandemic. Nowak, who is now a professor of health and risk communications at the University of Georgia, says communications about anything flu-related should start by leaning into the unknowable nature of flu.
“Flu viruses are very unpredictable and we don’t have a crystal ball to tell us how any flu virus is going to play out, whether it’s a seasonal flu virus, an avian flu virus. We just don’t know,” he said when we spoke recently about the challenges of H5N1 communications. “I think you always want to have that at the forefront versus trying to convey more certainty as a way to reduce or alleviate concern.”
Because I cover infectious diseases outbreaks — and covered H5N1’s twists and turns obsessively for a number of years — I have on occasion been accused of inciting panic or hyping threats that don’t materialize. (I would argue I’m just doing my job.) I remember in the early days of 2020, when experts were divided about what was going to happen with the new coronavirus, someone who had mocked me from time to time over the years on Twitter — X was still Twitter then — popped into my feed to ridicule me for making a mountain out of a molehill.
Covid was no molehill. But I am sensitive to the fact that not every looming outbreak will take off and that Covid-level events are blessedly rare. Public health officials know this, too. They tend to shy from calling the code, as epidemiologist Caitlin Rivers of Johns Hopkins’ Bloomberg School of Public Health wrote in her new book, “Crisis Averted.” (I reviewed it here.) I think that fear of being seen to be crying wolf may have caused public health officials to downplay the risk of Covid for too long in 2020. Paradoxically, the toxic hangover of the pandemic may make them even more reluctant to warn people of future disease threats.
So how should one talk about the risk H5N1 in cows poses? Nowak, who is on a National Academy of Sciences, Engineering and Medicine committee reviewing the CDC’s Covid-19 vaccine safety research and communications, said it depends on who you’re communicating to, and what you expect them to do with the information.
“You always want to know: Who are the priority audiences? Who really needs to have information about what we need to be doing to prepare for this?” he said, suggesting that right now the answer is probably policymakers facing decisions about how to prepare for the possibility of wider spread, farmworkers who need to be protected against the virus, and local public health officials on the lookout for human cases. It’s probably not people in general, Nowak said.
“You can’t really FYI the American public. We can FYI our friends but when you FYI the public and you’re a government agency like CDC or FDA … people are rightly going to say: Why are you telling me that? … What should I do with it?” he said. “You can’t simply say: ‘I just thought you ought to know.’”
With some exceptions — flu researchers, people who keep abreast of infectious disease science, and of course you, faithful readers — this outbreak probably isn’t hitting the radar of the average individual, Nowak said. “My assumption is that a lot of the messaging that is coming out of CDC is probably invisible to the public.”
I’ve been covering H5N1 since early 2004 and I’ve done plenty of worrying about it over the intervening years. But having followed it for so long, I no longer assume every unwelcome thing the virus does means we’re on the precipice of a pandemic. Still, I have never felt that this virus is something I can safely cross off my things-to-watch-closely list.
So I have no answer for the question: How much worrying should we be doing about H5N1 right now? But I take some solace from the fact that flu experts don’t either.
The world’s leading flu scientists recently met in Brisbane, Australia, for a key flu conference that is held once every two years, Options for the Control of Influenza. As you might expect, there was a lot of discussion — some on the program, some in the hallways — of the H5N1 outbreak in U.S. dairy cattle. But even there, among the best minds on influenza in the world, there was no clarity about the risk the situation poses, said Malik Peiris, chair of virology at the University of Hong Kong’s School of Public Health.
Peiris has been studying this virus since it first triggered human infections in 1997 in Hong Kong. He has a very healthy respect for its disruptive capacities. No one Peiris heard or spoke to suggested that H5N1 could never gain the ability to transmit easily from person-to-person. But likewise, no one appeared confident that widespread human-to-human transmission of this virus is inevitable or even highly likely, he said.
There was agreement, however, around at least one notion: Letting this virus continue to spread unchecked in cows is profoundly unwise.