Katherine J. Wu

After months and months of being told to wait, then wait, then wait some more, parents eager to vaccinate their littlest kids against COVID-19 have been gifted some good and very confusing news.

Two years into the pandemic, and two months into Omicron’s globe-crushing surge, our COVID-19 vaccines are finally on the cusp of a federally sanctioned update. To counter the new variant’s uncanny knack for slipping past antibodies roused by our first-generation shots, Moderna and Pfizer have both kick-started clinical trials to see how Omicron-specific vaccines fare in people.

Pour one out for Delta, the SARS-CoV-2 variant that Season 3 of the pandemic seems intent on killing off. After holding star billing through the summer and fall of 2021, Delta’s spent the past several weeks getting absolutely walloped by its feistier cousin Omicron—a virus that’s adept at both blitzing in and out of airways and dodging the antibodies that vaccines and other variants raise.

For many months now, Pfizer’s COVID-19 vaccine has been slowly making its way into smaller arms in smaller doses—from teens to adolescents to elementary-school-age kids in the fall. Now it’s just the under-5 crowd left, and the word on the lips of parents raring to protect their children is still, simply, when. Somehow, no one yet seems to know.

For weeks, the watchword on Omicron in much of America has been some form of phew. A flurry of reports has encouraged a relatively rosy view of the variant, compared with some of its predecessors. Omicron appears to somewhat spare the lungs. Infected laboratory mice and hamsters seem to handily fight it off. Proportionally, fewer of the people who catch it wind up hospitalized or dead. All of this has allowed a deceptively reassuring narrative to take root and grow: Omicron is mild.

If you’re trapped in COVID isolation right now, you’re making muffins. If that’s literally true, good for you, and I can recommend these. But I’m talking metaphorically. Right now, the infection you’re nursing, and the contagious risk it carries, is—hear me out—raw batter in an oven. You really, really don’t want to remove it too soon.Yes, we are in crisis right now. The pandemic’s been raging for two years, and I am talking about muffins.

On Tuesday, the CDC officially dropped the detailed, 1,800-word version of its new isolation guidance for people who have been infected by the coronavirus. So far, the best way I’ve got to sum it up is this: Hunker down for five days instead of the typical 10, then do what you want. ¯_(ツ)_/¯Okay, sorry, that’s overly simplistic.

For the past two years, Marie, a 30-something student in New York, had the right idea about COVID-19: She didn’t want to get it. Then, in the middle of December, as the antibody-dodging Omicron swept through her state, the coronavirus found her all the same. But Marie’s three vaccines helped keep her illness short and manageable.

Walter Barker has, since the fall of 2020, had five doses of COVID-19 vaccine. He’s already starting to ponder when he might need a sixth.Barker, a 38-year-old office worker in New York, received his first two doses a year ago, as part of an AstraZeneca vaccine trial. But the shots, which haven’t been authorized by the FDA, couldn’t get him into some venues. Sick of having to test every time he went to a Yankees game, Barker nabbed a pair of Moderna injections in the spring.

With Omicron, everything is sped up. The new variant is spreading fast and far. At a time when Delta was already sprinting around the country, Omicron not only caught up but overtook it, jumping from an estimated 13 to 73 percent of U.S. cases in a single week. We have less time to make decisions and less room to course-correct when they are wrong. Whereas we had months to prepare for Delta in the U.S., we’ve had only weeks for Omicron.

Killer T cells, as their name might imply, are not known for their mercy. When these immunological assassins happen upon a cell that’s been hijacked by a virus, their first instinct is to butcher. The killer T punches holes in the compromised cell and pumps in toxins to destroy it from the inside out. The cell shrinks and collapses; its perforated surface erupts in bubbles and boils, which slough away until little is left but fragmentary mush.

And there it is, the first trickle of data to confirm it. In the eyes of vaccinated immune systems, Omicron looks like a big old weirdo—but also, a kind of familiar one. That’s the verdict served up by several preliminary studies and press releases out this week, describing how well antibodies, isolated from the blood of vaccinated people, recognize and sequester the new variant in a lab.

If it doesn’t happen with this variant, it’ll happen with the next one, or maybe the next. Some version of this coronavirus is bound to flummox our vaccines. In the past two years, SARS-CoV-2 has hopscotched across the globe, rejiggering its genome to better coexist with us. The latest coronavirus contender, Omicron, has more than 50 mutations, making it the most heavily altered coronavirus variant of concern that researchers have identified to date.

As fall dips into winter in the Northern Hemisphere, the coronavirus has served up the holiday gift that no one, absolutely no one, asked for: a new variant of concern, dubbed Omicron by the World Health Organization on Friday.Omicron, also known as B.1.1.529, was first detected in Botswana and South Africa earlier this month, and very little is known about it so far. But the variant is moving fast.

As fall dips into winter in the Northern Hemisphere, the coronavirus has served up the holiday gift that no one, absolutely no one, asked for: a new variant of concern, dubbed Omicron by the World Health Organization on Friday.Omicron, also known as B.1.1.529, was first detected in Botswana and South Africa earlier this month, and very little is known about it so far. But the variant is moving fast.

Albatrosses do not fall in love the way humans do.When the birds couple up, it’s almost always for keeps. Their lives start lonely—albatross parents lay only one egg at a time, and may leave their offspring unattended for days—and at just a few months old, each juvenile embarks on an epic solo voyage at sea. They fly for months and months and months, learning what it is to be a bird.

In the spring of 2019, the biologist Tore Slagsvold headed into the forests outside Oslo to stage a series of tiny crime scenes. He didn’t need bullets, or bootprints, or even bodies or blood; only a handful of plush, white feathers.Slagsvold’s audience was avian—the region’s blue tits and pied flycatchers. And with any luck, his faux, fluffy evidence was going to scare the bejesus out of them.

A couple weeks ago at my local CVS, I spied them in the wild for the very first time—Abbott BinaxNOWs, currently America’s most sought-after rapid, at-home coronavirus test, piled neatly behind the counter.With the fall and winter holidays on the way, I figured it was a good opportunity to stock up. But after I asked for a few tests to cover my multi-person household, the pharmacist plucked just a single box off the stack.

For many, many months now, 7-year-old Alain Bell has been keeping a very ambitious list of the things he wants to do after he gets his COVID-19 shots: travel (to Disneyworld or Australia, ideally); play more competitive basketball; go to “any restaurants that have french fries, which are my favorite food,” he told me over the phone.These are very good kid goals, and they are, at last, in sight.

Some good news finally—finally—appears to be on the horizon for roughly 28 million of the United States’ youngest residents. On the heels of an advisory meeting convened yesterday, the FDA is likely on the cusp of green-lighting a kid-size dose of Pfizer’s COVID-19 vaccine for Americans ages 5 to 11, a move that’s been months in the making.

Some cuckoos are born assassins. Within a day or two of hatching, the infant birds—still blind, pink, and featherless—will start to evict the other residents of their nest, hurling them over the edge and to their death.Technically, the evictions they carry out are from living quarters that aren’t even their own. The cuckoos are parasites, strategically placed by their mother into the abode of another species so they can mooch their way through adolescence.

Mixing and matching vaccine brands is officially on the table in the United States. But that option might soon be billed as the B-list choice.Last night, CDC Director Rochelle Walensky gave the green light for Moderna and Johnson & Johnson booster shots, the long-awaited follow-up to a similar recommendation given to the Pfizer formulation last month.

In early March, Deepta Bhattacharya, an immunologist at the University of Arizona, celebrated a milestone: hitting the point of full vaccination, two weeks after getting his second Pfizer shot. Since then, he’s been watching the number of coronavirus antibodies in his blood slowly but surely decline.

One of the best and toughest parts of being a science writer is acting as a kind of jargon liaison. Weird, obscure, aggressively multisyllabic words appear in scientific discourse; I, wielding nothing but a Google Doc, a cellphone, and the Powers of the Internet™, wrest these terms from their academic hidey-holes and try to pin them down with some endearing yet accurate analogy.

Two years into the pandemic, we’ve gotten a lot better at tackling the coronavirus at the extremes of infection. We have preventives—including masks, distancing, ventilation, and our MVP vaccines—that can be deployed in advance of a viral encounter. We have regimens of last resort: drugs, such as dexamethasone, that do their best, lifesaving work in hospitals with trained health-care workers, in patients whose disease has already turned severe.

Studying sea slugs in the group Sacoglossa can mean being on the receiving end of some very imaginative emails. Sidney K. Pierce, of the University of South Florida, retired a few years ago. “But to this day,” he told me, “I get questions from little kids in their science classes” who have stumbled upon the marvelous mollusks—and want to know if they could help “end world hunger.”The answer, Pierce assured me, is no.

Editor’s Note: This article is part of our coverage of The Atlantic Festival. Learn more and watch festival sessions here. For some of us, booster shots have finally arrived. But they’ve charted quite a meandering course to get here. First, last month, President Joe Biden announced that most Americans would be able to nab third doses of mRNA vaccines eight months after their second shots.

For nearly two years now, Americans have lived with SARS-CoV-2. We know it better than we once did. We know that it can set off both acute and chronic illness, that it spreads best indoors, that masks help block it, that our vaccines are powerful against it. We know that we can live with it—that we’re going to have to live with it—but that it can and will exact a heavy toll.Still, this virus has the capacity to surprise us, especially if we’re not paying attention.

Immune cells can learn the vagaries of a particular infectious disease in two main ways. The first is bona fide infection, and it’s a lot like being schooled in a war zone, where any lesson in protection might come at a terrible cost. Vaccines, by contrast, safely introduce immune cells to only the harmless mimic of a microbe, the immunological equivalent of training guards to recognize invaders before they ever show their face.

In 1846, the Danish physician Peter Ludvig Panum traveled to the Faroe Islands in search of measles. The rocky archipelago, which sits some 200 miles north of Scotland, had been slammed with an outbreak, and Panum was dispatched by his government to investigate.