Tag: recent memory

The Other Group of Viruses That Could Cause the Next Pandemic

Whether it begins next week, next year, or next decade, another pandemic is on its way. Researchers can’t predict precisely when or how the outbreak might begin. Some 1.6 million viruses are estimated to lurk in the world’s mammalian and avian wildlife, up to half of which could spill into humans; an untold number are attempting exactly that, at this very moment, bumping up against the people hunting, eating, and encroaching on those creatures. (And that’s just viruses: Parasites, fungi, and bacteria represent major infectious dangers too.) The only true certainty in the pandemic forecast is that the next threat will be here sooner than anyone would like.

But scientists can at least make an educated guess about what might catalyze the next Big One. Three main families of viruses, more than most others, keep scientists up at night: flu viruses, coronaviruses, and paramyxoviruses, in descending order of threat. Together, those groups make up “the trifecta of respiratory death,” Sara Cherry, a virologist at the University of Pennsylvania, told me.

Flu and coronavirus have a recent track record of trouble: Since 1918, flu viruses have sparked four pandemics, all the while continuing to pester us on a seasonal basis; some scientists worry that another major human outbreak may be brewing now, as multiple H5 flu viruses continue to spread from birds to mammals. The past two decades have also featured three major and deadly coronavirus outbreaks: the original SARS epidemic that began in late 2002; MERS, which spilled into humans—likely from camels—in 2012; and SARS-CoV-2, the pandemic pathogen that’s been plaguing us since the end of 2019. Common-cold-causing coronaviruses, too, remain a fixture of daily living—likely relics of ancient animal-to-human spillovers that we kept transmitting amongst ourselves.

Read: Bird flu has never done this before

Paramyxoviruses, meanwhile, have mostly been “simmering in the background,” says Raina Plowright, a disease ecologist at Cornell. Unlike flu viruses and coronaviruses, which have already clearly “proven themselves” as tier-one outbreak risks, paramyxoviruses haven’t yet been caught causing a bona fide pandemic. But they seem poised to do so, and they likely have managed the feat in the past. Like flu viruses and coronaviruses, paramyxoviruses can spread through the air, sometimes very rapidly. That’s certainly been the case with measles, a paramyxovirus that is “literally the most transmissible human virus on the planet,” says Paul Duprex, a virologist at the University of Pittsburgh. And, like flu viruses and coronaviruses, paramyxoviruses are found in a wide range of animals; more are being discovered wherever researchers look. Consider canine distemper virus, which has been found in, yes, canines, but also in raccoons, skunks, ferrets, otters, badgers, tigers, and seals. Paramyxoviruses, like flu viruses and coronaviruses, have also repeatedly shown their potential to hopscotch from those wild creatures into us. Since 1994, Hendra virus has caused multiple highly lethal outbreaks in horses, killing four humans along the way; the closely related Nipah virus has, since 1998, spread repeatedly among both pigs and people, carrying fatality rates that can soar upwards of 50 percent.

The human versions of those past few outbreaks have petered out. But that may not always be the case—for Nipah, or for another paramyxovirus that’s yet to emerge. It’s entirely possible, Plowright told me, that the world may soon encounter a new paramyxovirus that’s both highly transmissible and ultra deadly—an “absolutely catastrophic” scenario, she said, that could dwarf the death toll of any epidemic in recent memory. (In the past four years, COVID-19, a disease with a fatality rate well below Nipah’s, has killed an estimated 7 million people.)

All that said, though, paramyxoviruses are a third-place contender for several good reasons. Whereas flu viruses and coronaviruses are speedy shape-shifters—they frequently tweak their own genomes and exchange genetic material with others of their own kind—paramyxoviruses have historically been a bit more reluctant to change. “That takes them down a level,” says Danielle Anderson, a virologist at the Doherty Institute, in Melbourne. For one, these viruses’ sluggishness could make it much tougher for them to acquire transmission-boosting traits or adapt rapidly to spread among new hosts. Nipah virus, for instance, can spread among people via respiratory droplets at close contact. But even though it’s had many chances to do so, “it still hasn’t gotten very good at transmitting among humans,” Patricia Thibault, a biologist at the University of Saskatchewan who studied paramyxoviruses for years, told me.

The genetic stability of paramyxoviruses can also make them straightforward to vaccinate against. Our flu and coronavirus shots need regular updates—as often as annually—to keep our immune system apace with viral evolution. But we’ve been using essentially the same measles vaccine for more than half a century, Duprex told me, and immunity to the virus seems to last for decades. Strong, durable vaccines are one of the main reasons that several countries have managed to eliminate measles—and why a paramyxovirus called rinderpest, once a major scourge of cattle, is one of the only infectious diseases we’ve ever managed to eradicate. In both cases, it helped that the paramyxovirus at play wasn’t great at infecting a ton of different animals: Measles is almost exclusive to us; rinderpest primarily troubled cows and their close kin. Most flu viruses and SARS-CoV-2, meanwhile, can spread widely across the tree of animal life; “I don’t know how you can eradicate that,” Anderson told me.

The problem with all of these trends, though, is that they represent only what researchers know of the paramyxoviruses they’ve studied—which is, inevitably, a paltry subset of what exists, says Benhur Lee, a virologist at Mount Sinai’s Icahn School of Medicine. “The devil we don’t know can be just as frightening,” if not more, Lee told me. A pattern-defying paramyxovirus may already be readying itself to jump.

Researchers are keyed into these looming threats. The World Health Organization highlights Nipah virus and its close cousins as some of its top-priority pathogens; in the U.S., paramyxoviruses recently made a National Institute of Allergy and Infectious Diseases list of pathogens essential to study for pandemic preparedness. Last year, the Bill & Melinda Gates Foundation announced a hefty initiative to fund paramyxovirus antiviral drugs. Several new paramyxovirus vaccines—many of them targeting Nipah viruses and their close relatives—may soon be ready to debut.

Read: We have a mink problem

At the same time, though, paramyxoviruses remain neglected—at least relative to the sheer perils they pose, experts told me. “Influenza has been sequenced to death,” Lee said. (That’s now pretty true for SARS-CoV-2 as well.) Paramyxoviruses, meanwhile, aren’t regularly surveilled for; development of their treatments and vaccines also commands less attention, especially outside of Nipah and its kin. And although the family has been plaguing us for countless generations, researchers still don’t know exactly how paramyxoviruses move into new species, or what mutations they would need to become more transmissible among us; they don’t know why some paramyxoviruses spark only minor respiratory infections, whereas others run amok through the body until the host is dead.

Even the paramyxoviruses that feel somewhat familiar are still surprising us. In recent years, scientists have begun to realize that immunity to the paramyxovirus mumps, once thought to be pretty long-lasting and robust, wanes in the first few decades after vaccination; a version of the virus, once thought to be a problem only for humans and a few other primates, has also been detected in bats. For these and other reasons, rubulaviruses—the paramyxovirus subfamily that includes mumps—are among the potential pandemic agents that most concern Duprex. Emmie de Wit, the chief of the molecular-pathogenesis unit at Rocky Mountain Laboratories, told me that the world could also become more vulnerable to morbilliviruses, the subfamily that includes measles. If measles is ever eradicated, some regulators may push for an end to measles shots. But in the same way that the end of smallpox vaccination left the world vulnerable to mpox, the fall of measles immunity could leave an opening for a close cousin to rise.

The next pandemic won’t necessarily be a paramyxovirus, or even a flu virus or a coronavirus. But it has an excellent chance of starting as so many other known pandemics have—with a spillover from animals, in parts of the world where we’ve invaded wild habitats. We may not be able to predict which pathogen or creature might be involved in our next big outbreak, but the common denominator will always be us.

Katherine J. Wu

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October 29, 2023
Now Is the Perfect Time to Role-Play a Pandemic

In October 2019, just a few months before a novel coronavirus sparked a deadly pandemic, a group of government officials, business leaders, and academics convened in New York City to role-play a scenario in which a novel coronavirus sparked a deadly pandemic. Their imagined virus leaped from livestock to farmers in Brazil, then spread to Portugal, the United States, and China. Soon, it was everywhere. Eighteen months later, 65 million people were dead.

This simulation, known as Event 201, was one of dozens of so-called pandemic war games run in the two decades leading up to the outbreak of COVID-19. In mid-2020, as the world came to terms with its new pandemic reality, media outlets published a flood of articles about these simulations. Some highlighted their prescience, others their blind spots. But the real-world crisis that occasioned this review was only a few months old. Whatever hindsight it provided wasn’t yet in focus, because many of the greatest challenges of the pandemic—new variants, vaccine hesitancy, the hyper-politicization of public health—were still to come.

Almost three years later, we know that the war-gamers whiffed on many of these longer-term outcomes. Pre-pandemic role-plays successfully predicted early events like the overwhelming of the nation’s hospitals, ineffective travel bans, and a lack of coordination across levels of government. But they underestimated the significance of masking policies, the speed at which vaccines would be developed, and the politicized backlash to those interventions. They also failed to account for cascading viral evolution, and did not grasp how long such a crisis could last. “The scenario ends at the 18-month point,” the makers of Event 201 wrote. “The pandemic is beginning to slow due to the decreasing number of susceptible people. The pandemic will continue at some rate until there is an effective vaccine or until 80–90% of the global population has been exposed.” If only.

Read: The next plague is coming. Is America ready?

War-gamers are trying to learn from their mistakes. Long before any public-health authority had declared the acute phase of the pandemic over, officials were already playing out fresh scenarios that better fit the facts. At the Munich Security Conference in February 2022, for example, the Johns Hopkins Center for Health Security helped run an exercise focused on rapid development and equitable distribution of vaccines for an imagined future virus, Tom Inglesby, the center’s director, told me. Later that year, at an annual meeting convened in Brussels by the WHO and the Bill & Melinda Gates Foundation, the same group ran a simulation in which current and former foreign ministers had to grapple with the threats of misinformation and resistance to non-pharmaceutical interventions. Unlike pre-pandemic war games, this one also took into account governments’ attitudes toward expert public-health advice.

Accounting for the specific facts of the coronavirus pandemic could make future war games more realistic, experts told me, but it won’t ensure that they have substantive value. These exercises are not meant to predict what will happen in the next pandemic, so much as to prepare for what might happen. Bringing games into alignment with recent experience matters only insofar as it conduces to the latter.

War-gamers often draw a distinction between tabletop exercises and functional exercises. In the former, participants sit around discussing what they would do in a given scenario; in the latter, participants actually do it. They might transport stockpiled resources, distribute personal protective equipment, or care for pretend patients at a hospital. The Pentagon moves real forces around the world as part of its simulations. This real-world practice is sorely needed for pandemic scenarios, too, says Jennifer Nuzzo, the director of Brown University’s Pandemic Center. “When I look back at COVID, many of the failings stemmed from the fact that we didn’t functionally exercise enough of the capacities that we supposedly had.”

Pandemic exercises could also be made more challenging, Inglesby said. Too many are set up to prevent participants from feeling demoralized, he said, as opposed to “exercising to the point of failure.” This principle can be taken too far, though, Nuzzo told me. If the exercise is too intense, people get overwhelmed and disengage. Real pandemics, of course, are highly overwhelming, but if you’re trying to train someone to bench-press their weight, you can’t just drop a 200-pound barbell on their chest and shout “Go!” They have to build up strength over time.

Read: The boardgames that ask you to reenact colonialism

Coming through an actual pandemic is a form of training, too, but that experience doesn’t make war games useless. In fact, they may be more important now than ever, experts told me. Before COVID, pandemic role-plays were meant in part to raise awareness—to show participants and the public alike that a pandemic could really happen. Now, obviously, few people need to be persuaded of the risk. Post-COVID, the exercises serve a very different function: They remind us that the next pandemic might look nothing like the one we’ve just experienced. It could have a far higher case-fatality rate. It could disproportionately sicken children rather than the elderly. Its symptoms could be neurological instead of respiratory. “Just having lived through COVID doesn’t prepare us for all future events,” Inglesby said. Experience is an infinitesimal sliver of possibility.

We try, through war games, to internalize this. It is not always easy. Event 201 notwithstanding, pandemic simulations have traditionally focused too much on influenza and not enough on other pathogens, perhaps because of how many outbreaks the former has caused in the past. It would be just as wrong to focus only on coronaviruses now, and leave influenza behind. At the simulation in Brussels, Eric Toner, a senior scholar at the Johns Hopkins Center for Health Security, told me, some participants struggled not to default to recent memory: “They kept coming back to, ‘Well, in COVID we did this,’ or ‘In COVID we did that.’” It’s a delicate balance to strike: to learn from experience without being constrained by it.

Jacob Stern

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May 30, 2023
The Great Senate Stalemate

The map of competitive Senate elections is shrinking—and not just for November.

Though Republicans began the year expecting sweeping Senate gains, the party’s top-grade opportunities to capture seats now held by Democrats have dwindled to just two—Nevada and Georgia—and both are, at best, toss-ups for the GOP. And while Democrats, somewhat astoundingly, have emerged from the primaries with at least as many plausible flipping chances as Republicans, Pennsylvania is the only GOP-held seat clearly favored to go blue, and even that isn’t guaranteed. It remains entirely possible that November’s results will leave the Senate divided again at 50–50, something that has not happened in consecutive elections since the Seventeenth Amendment established the direct election of senators more than a century ago.

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This standoff partly reflects the volatile dynamics of the 2022 election, in which Republican advantages on the economy have been largely neutralized by public unease over gun violence, the Supreme Court’s abortion ruling, the resurgent visibility of former President Donald Trump, and the GOP’s nomination of weak, Trump-aligned candidates. Yet the possibility of a virtual draw—after a campaign season in which the two sides have already poured more than $850 million into just the 10 most expensive Senate races—reflects larger changes in the electoral competition.

One of the most powerful trends in modern politics has been for each party to consolidate control of the Senate seats in the states it usually captures in the presidential election. That’s lowered the ceiling on the number of Senate seats each party can win. And that lowered ceiling, in turn, has diminished each side’s ability to maintain control of the Senate majority for any extended period.

The Senate is therefore frozen in the sense that neither side, in normal times, can seriously contest more than a handful of the seats held by the other party. Paradoxically, it’s unstable in the sense that the shrunken playing field leaves each side clinging to tiny majorities that are vulnerable to small shifts in voter attitudes in the very few states that remain consistently competitive.

Throughout the 20th century, it was common for one side to build a comfortable majority in which it held at least 55 percent of the Senate’s seats. Republicans hit that level of dominance in 10 of the 15 Congresses from 1901 through 1930. Then, from 1932 to 1980, Democrats regularly reached the 55 percent threshold. (The big exception to this pattern came in the 1950s, when the ideological lines between the parties blurred and neither won more than a two-seat Senate majority through four consecutive Congresses.) Even from 1980 to 2000, one side or the other reached 55 seats seven times. Since 2000, though, the parties have controlled at least 55 seats only three times: Republicans immediately after George W. Bush’s reelection in 2004 and Democrats immediately after Barack Obama’s presidential victories in 2008 and 2012.

Smaller margins have reduced both parties’ ability to defend their majorities for any extended period. Since 1980, neither party has controlled the Senate for more than eight consecutive years. That’s unprecedented: The U.S. has never gone four decades without a Senate majority that survived for more than eight years.

Both the thin margins and frequent turnover are rooted in a third trend: the growing alignment between states’ votes for president and Senate.

Especially through the second half of the 20th century, states routinely supported presidential candidates from one party and Senate candidates from the other. After the landslide reelections of Richard Nixon in 1972 and Ronald Reagan in 1984, for instance, Democrats still controlled about half of the Senate seats in the states that voted for them both times.

But as American politics has grown more partisan and parliamentary, those split-ticket senators have virtually gone extinct, which has reduced the number of states each side can realistically contest.

Read: Voters don’t split tickets anymore

After the 2020 election, the GOP held 94 percent of the Senate seats in the 25 states that voted for Trump both times while Democrats held 98 percent of the seats in the 20 states that twice voted against him. Democrats have squeezed out their current 50–50 Senate majority by winning eight of the 10 Senate seats in the remaining five swing states that switched from Trump to Joe Biden.

Last spring, Republicans anticipated a midterm red wave that would break this stalemate, followed by a push toward a filibuster-proof 60-seat Senate majority in 2024.

Both parties identified Catherine Cortez Masto in Nevada, Raphael Warnock in Georgia, Mark Kelly in Arizona, and Maggie Hassan in New Hampshire as the most vulnerable Democratic senators. Beyond that, Republicans hoped to seriously challenge Michael Bennet in Colorado and Patty Murray in Washington. The 2022 electoral environment remains unsettled, and it’s possible that continuing discontent over the economy could improve GOP prospects before election day. But for now, with Colorado, Washington, Arizona, and New Hampshire all moving toward the Democrats, it appears that the list of fully plausible GOP Senate targets has fallen to just two: Nevada and Georgia.

All polls in Georgia show a tight race between Warnock and the Republican nominee, Herschel Walker, the former University of Georgia football star. And with Republican Governor Brian Kemp holding a steady lead over Democrat Stacey Abrams, it remains possible that a Georgia crimson tide (pun intended) might carry Walker to victory. But Walker may be the most obviously unqualified Senate nominee in recent memory, and he’s facing a seemingly endless procession of personal scandals. Walker’s vulnerabilities might allow Warnock to survive even a strong Republican current; indeed all but one of the five most recent public polls have shown Warnock in the lead.

That leaves Nevada as the best chance for Republicans to capture a seat Democrats hold now. A state with legions of low-wage workers, Nevada has heavily felt the effects of coronavirus shutdowns and inflation. The state also lacks the large pool of college graduates and white-collar professionals heavily motivated by abortion and other social issues lifting Democrats elsewhere. But even with all that boosting them, Republicans can hardly be confident about Nevada: For longer than the past decade, Nevada Democrats, operating the political machine assembled by the late former Senate Majority Leader Harry Reid, have shown a knack for turning out just enough of their voters to win very close races.

Democrats, unexpectedly, have kept a larger roster of GOP Senate seats in play. The Senate race most likely to change hands between the parties remains Pennsylvania, where Republican Pat Toomey is retiring. Democratic Lieutenant Governor John Fetterman, although some polls show his margin narrowing, remains favored over Mehmet Oz, the Republican nominee. Oz is laboring under strong unfavorable ratings and will likely face an undertow from the governor’s race, where Doug Mastriano, among the most extreme GOP nominees anywhere this year, could face a crushing defeat.

Polls also show Democrats Mandela Barnes and Tim Ryan locked in margin-of-error races in Wisconsin and Ohio. Barnes and Ryan have given themselves a realistic chance to win against GOP opponents who are also laboring under high unfavorable ratings, Senator Ron Johnson in Wisconsin and J. D. Vance in Ohio. But those are both states where Democrats often struggle to find the last few percentage points of support they need, and this will especially be the case while Biden’s approval rating is depressed among the white non-college voters so plentiful in each.

Read: What the primaries reveal about the future of Trumpism

In North Carolina, Democrat Cheri Beasley is likewise step for step in polls with Republican Ted Budd—though, since 2008, that state has functioned as a kind of heartbreak hill for Democrats, who have suffered a succession of narrow defeats there. Florida has become an even tougher state for Democrats, but polls have consistently shown Democratic Representative Val Demings remaining closer to Republican Senator Marco Rubio than most analysts initially expected.

This playing field still leaves Republicans a path to a majority, but one much narrower than they anticipated. If the GOP loses Pennsylvania, which remains likely, its most plausible path to retake the Senate is to win both Nevada and Georgia, while simultaneously holding off the Democrats in both Wisconsin and Ohio, not to mention North Carolina and Florida. Republican upsets in Arizona or New Hampshire, or Oz surging past Fetterman during the final weeks in Pennsylvania, would ease that pressure. But today, none of those outcomes look probable.

Yet even if Democrats hold the Senate, it will likely be with a very narrow majority, and perhaps with nothing more than another 50–50 tie that Vice President Kamala Harris will step in to break. Democrats would still remain at substantial risk of surrendering their majority in 2024, largely because they will be defending all three of the seats they hold in the states that twice voted for Trump—Joe Manchin in West Virginia, Jon Tester in Montana, and Sherrod Brown in Ohio. That won’t be easy in a presidential-election year.

Early in Biden’s presidency, some Democratic strategists, such as the data analyst David Shor, ominously warned that the party could face an extended period of Republican dominance in the Senate, largely because of the GOP’s hardening advantage in heavily white interior states. The GOP probably does hold an edge in the long-term battle for Senate control because it is regularly winning slightly more states than Democrats in presidential contests. But the fizzling of the GOP’s Senate opportunities this year shows how difficult it may be for either side to secure a sizable, much less durable, majority.

Political scientists and strategists alike usually find far more meaning in elections that deliver resounding change than those that reconfirm the status quo. Yet it will send a powerful message if neither party in November can break through the forces that have left the Senate so precariously balanced. It will show that the two sides remain locked in a grinding trench warfare where neither can overwhelm the other’s defenses and the handful of states in the no-man’s-land between them hold decisive power to tilt the national direction. That’s a recipe for more years of bitter but inconclusive conflict between two political coalitions that are now almost identical in size—but utterly antithetical in their vision for America’s future.

Ronald Brownstein

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September 28, 2022