If the United States has been riding a COVID-19 ’coaster for the past two-plus years, New York and a flush of states in the Northeast have consistently been seated in the train’s front car. And right now, in those parts of the country, coronavirus cases are, once again, going up. The rest of America may soon follow, now that BA.2—the more annoying, faster-spreading sister of the original Omicron variant, BA.1—has overtaken its sibling to become the nation’s dominant version of SARS-CoV-2.  

Technologically and immunologically speaking, Americans should be well prepared to duel a new iteration of SARS-CoV-2, with two years of vaccines, testing, treatment, masking, ventilation, and distancing know-how in hand. Our immunity from BA.1 is also relatively fresh, and the weather’s rapidly warming. In theory, the nation could be poised to stem BA.2’s inbound tide, and make this variant’s cameo our least devastating to date.

But theory, at this point, seems unlikely to translate into practice. As national concern for COVID withers, the country’s capacity to track the coronavirus is on a decided downswing. Community test sites are closing, and even the enthusiasm for at-home tests seems to be on a serious wane; even though Senate Majority Leader Chuck Schumer announced a new deal on domestic pandemic funding, those patterns could stick. Testing and case reporting are now so “abysmal” that we’re losing sight of essential transmission trends, says Jessica Malaty Rivera, a research fellow at Boston Children’s Hospital. “It’s so bad that I could never look at the data and make any informed choice.” Testing is how individuals, communities, and experts stay on top of where the virus is and whom it’s impacting; it’s also one of the main bases of the CDC’s new guidance on when to mask up again. Without it, the nation’s ability to forecast whatever wave might come around next is bound to be clouded.

[Read: America is about to test how long “normal” can hold]

We can’t react to a wave we don’t see coming. “I keep thinking back to this idea of If we don’t measure it, it won’t happen,” says Shweta Bansal, an infectious-disease modeler at Georgetown University. (As President Donald Trump once put it, “If we stop testing, we’d have fewer cases.”) In reality, “it’s very well happening, and we just don’t see it yet.” There is still no guarantee that the next wave is nigh—but if it is, the U.S. is poorly positioned to meet it. Americans’ motivational tanks are near empty; the country’s stance has, for months, been pretty much whatevs. The next wave may be less a BA.2 wave, and more a so what? wave—one many Americans care little to see, because, after two years of crisis, they care so little to respond.


Colloquially, epidemiologically, a wave is a pretty squishy term, a “know it when you see it” notion that gets subjective, fast. “There is no technical definition,” says C. Brandon Ogbunu, a mathematical modeler studying infectious-disease dynamics at Yale. And with COVID-19, there’s no consensus among experts on exactly when waves begin or end, or how sharp or tall one must be to count.

A reasonable delineation for a wave might involve an unexpected deviation from a baseline low—a sudden and sustained uptick in cases that eventually trends back down. That concept might seem intuitive, and yet it’s rife with assumptions: Unexpected, baseline, sudden, sustained—all of these require prior intel on how a disease typically behaves, says Justin Lessler, an infectious-disease modeler at the University of North Carolina at Chapel Hill. Researchers have spent decades building those knowledge bases for diseases like the flu. But “we don’t know what ‘normal’ conditions for COVID-19 are going to look like yet,” he told me.

That makes the start of a wave tough to identify even when testing data abound; no single inflection point guarantees a shift from not a wave to definitely a wave. Technically, the BA.1 wave that reached its zenith in mid-January may not have even ended yet, because experts haven’t decided what threshold it would need to reach to do so. Lessler proposed that last summer’s pre-Delta nadir might serve as a tentative benchmark. “If we were sustained there, it wouldn’t be the worst thing ever,” he told me. But despite the relief much of the nation has been feeling the past couple of months, “most places haven’t even gotten there.”

Still, new waves can begin before their predecessors conclude. The experts I spoke with said that an increase in SARS-CoV-2 cases that ratcheted up counts by more than a couple percentage points a week, lasted at least 14ish days, and impacted a large swath of the country, would definitely trip alarm bells. On the whole, the United States does not seem to be at alarm-bell level quite yet, Ogbunu told me. Maybe, if cases don’t rise sharply enough, or to a high enough amplitude, the country won’t get there with BA.2 at all. But it’s too soon to tell. The latest estimates put BA.2 at the root of about 70 percent of sequenced infections in the United States. That’s right past the proportion at which BA.2 started putting a serious squeeze on other countries, says Sam Scarpino, the managing director of pathogen surveillance at the Rockefeller Foundation. “Once you get into the 50 to 60 percent BA.2 range is when you see cases going up,” he told me. Experts can’t yet know if the U.S. will be more resilient, or less.

Watching only the national curve can also be misleading. Country-wide data show only a gargantuan average; these numbers smooth and conceal the case rises that have already been erupting in isolated patchworks. That sort of variability is a product of where humans have carried this new subvariant; of the immune landscape that vaccinations and past versions of the virus have left behind; and of the local defenses, such as masking (or not), that people are leveraging against BA.2, says Bansal, who’s been leading efforts to map how different communities will be impacted by future variants. And patchiness is to be expected. And these more regional waves still matter, even if they seem at first easier to ignore.

[Read: Will Omicron leave most of us immune?]

They will, in many cases, mark the places least prepared to weather another surge in infections. Tests, while more abundant, have remained inaccessible to many of those who need them; without tests, treatments, too, will drift out of reach. And Malaty Rivera worries that, even now, we don’t know which parts of the country are being hardest hit, thanks to underdiagnosis and underreporting. Some places that appear to be coasting on plateaus or trending down may not be as well positioned as they first seem. Wastewater surveillance, which homes in on virus particles extruded in waste, could help—but these monitoring sides aren’t distributed evenly, either. As things stand, the national map of where the virus is moving is full of blank spots and dark patches. Even unmeasured waves, if they grow big enough, have ways of breaking over us. At worst, the virus could eventually surprise us with a rash of hospitalizations—a sign that the initial bump of cases, one we should have responded to, is already in our rearview mirror.


Not all case rises have to spell disaster. Since November, when Omicron was first identified, more Americans have been vaccinated for the first time, or boosted, or infected; rapid tests have become more available; and the oral antiviral Paxlovid has hit far more pharmacy shelves. All these factors, plus a springtime flocking into the outdoors, especially in the northern U.S., could help blunt a potential wave’s peak; some may even help uncouple a rise in infections from a secondary surge in hospitalizations and deaths. “Those are the numbers I’m more interested in,” says David S. Jones, a historian of science at Harvard University. If cases go up, but the most severe outcomes stay trim, Jones told me, he’ll feel far less concerned; this wave won’t have to feel like the one the country just weathered, by any stretch.

It’s certainly a reasonable future to hope for, but not an outcome that can be taken for granted. Even now, less than half of Americans are boosted, and health-care systems and their workers are reeling from the most recent surge. And although the Senate has reached a deal on an additional $10 billion of emergency funds for pandemic prevention efforts, that sum is less than half of the original $22.5 billion the Biden administration originally asked for. Without more money to keep mitigation tools flowing freely into the community, Bansal also worries about the implications of focusing too hard on hospitalizations. Taking a so-what approach until a substantial number of severe cases show up, as CDC guidance advises Americans do, is “just too late,” she told me. “The story’s already been written for those individuals who have been infected.” Nor are hospitalizations and deaths the only outcomes that matter, as millions of people in the United States alone continue to grapple with the debilitating symptoms of long COVID, which vaccines only partly diminish.

Outbreaks are dialogues; rises in cases can be driven by a new version of the virus, but also by us. Nearly two years ago, Jones and Stefan Helmreich, an anthropologist at MIT, warned that speaking of epidemics as waves casts them “as natural phenomena”—disasters that blow through us, in ways beyond our control. But the trajectory of an epidemic is actually “deeply shaped by human action, both before such disasters hit and as they are managed,” they wrote. Waves don’t just happen to us. They are also, unlike the ocean swells they evoke, shaped by us. Scientifically, calling whatever’s coming a “BA.2 wave” is fair, because BA.2 is ousting its competitors. Still, its peculiarities—or the peculiarity of any next wave—might be less about the quirks of the variants involved and more about how readily we respond. (Certainly, if it’s not BA.2 that troubles us imminently, it’ll be another SARS-CoV-2 offshoot.)

Human actions can slow rises in cases. They can also accelerate them. And when infections take off, it’s not always easy to tell who holds the steering wheel—pathogen or host. “Every outbreak since the beginning of humankind has a behavioral component, an immunological component, and a viral component,” Yale’s Ogbunu told me. “Where one ends and another begins is never completely clear.” But Americans are too far along in this pandemic, and too familiar with the tools we need to manage it, to shirk culpability entirely. Pre-vaccine variants pummeled us when we were poorly defended. The antibody-dodging BA.1 circumvented some of our immune shields. BA.2 isn’t a perfect match for our shots, either. And yet, fresh off of its sibling’s winter crush, we would be remiss to be twice fooled.

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