The Post-COVID “Immunity Gap” Continues to Pummel Pediatric Wards

It’s after 9 P.M., and I’m with the pediatric night team in the children’s emergency room at my hospital. We’re admitting another toddler with a viral infection. The kid has the flu, or RSV, parainfluenza, rhinovirus, adenovirus, COVID, enterovirus, or some mix of multiple viruses—it hardly matters. She is coming into the hospital so that we can help her breathe. Tonight, as is the case in children’s hospitals across the country, we don’t have a room available in our ward for the new patient. She will stay in the emergency room overnight, but we pediatricians will take over her care so that the E.R. docs can focus on the other sick kids who continue to arrive.

In recent months, children nationwide have been struggling through widespread and severe viral outbreaks. Frequent illnesses and hospitalizations have strained pediatric health systems, and, last month, the American Academy of Pediatrics (A.A.P.) and the Children’s Hospital Association asked the Biden Administration to declare a national emergency. The crisis continues, and we are facing local shortages of fever medicines as well as a national shortage of one of our most important and commonly used liquid antibiotics, amoxicillin.

Lately, most of the kids who we admit have viral infections. When your lungs are the size of ice-cream sandwiches and your largest airway is about as wide as my pinkie finger, it’s easy for inflammation and secretions from viruses to clog things up. But some kids will also have bacterial infections: pneumonias, meningitis, and infections in their ears, urinary tract, and—in the case of more invasive infections such as septicemia—in the bloodstream. Viral infections put children at risk for these dangerous secondary infections. To keep them safe, my team needs to figure out which kids need antibiotics and which do not. Liquid amoxicillin would normally be the preferred antibiotic for many of these patients: it is safe, effective, and palatable for young kids. While we’ve been able to get it here in the hospital, outpatient pediatricians are substituting broader-spectrum antibiotics or calling from pharmacy to pharmacy in search of amoxicillin. In the context of the shortage, pediatricians are advised to “watch and wait,” and forgo antibiotics whenever we safely can—a practice that pediatricians generally follow anyway. Unnecessary antibiotics only place children at risk for side effects and harm.

Most of the work of determining which kids are in danger relies on experience rather than technology. The viruses themselves can be dangerous; RSV kills tens of thousands of children worldwide every year, and the flu has already killed forty-seven American children this season. In addition to supporting kids’ breathing, we examine them for signs of an obvious secondary infection: pus behind an eardrum, crackling noises centered on one area of a lung, a muffled voice, certain rashes. We look for indications of crumping: low blood pressure, an altered mental state, holding still in bed from pain, seizing. We occasionally need a chest X-ray or labs.

The rest of our diagnosis—a significant chunk—comes from the family’s story of how the illness has progressed. We try hard to ascertain how long fevers have lasted, and whether they’ve come and gone. A fever that lasts five days, goes away, and then recurs a day or two later could be a sign of danger. (Or the kid might have just caught a second virus right after the first one.) The timing is important because, for that small percentage of preschoolers who have bacterial pneumonia, the bacteria will almost always come on the tail of a virus. But no single factor—not a chest X-ray, not an oxygen level, not a physical-exam finding—can reliably distinguish between bacterial and viral pneumonia in children. Making this call requires putting together a complex array of information, as well as clinical judgment.

A particular difficulty this December is that so many kids in day care or preschool have been sick on and off since August. When I ask parents how long their toddler has been sick, a few are able to name a number of days. Some look up at the ceiling. They spread their palms. They bare their teeth. They say, “I don’t know” or “Three weeks?” or “It seems like he’s been sick forever.”

Once upon a time, I might have been frustrated by this inability to give a detailed history of a young child’s illness. How do you not know how long your kid has had a fever? I might’ve considered terms like “low health literacy” or “social stressors.”

These days, though, I am the mother of a vigorous two-and-a-half-year-old, Sam, who is in day care, and I have no idea how long he’s been sick. He was definitely sick last weekend with fevers that started maybe Thursday? He’s still coughing a lot at night. I’m sure that he didn’t have a fever on Monday, because we kept him home from day care for a Sunday-night fever, but then he was O.K. Before that, he was definitely sick on Thanksgiving. And at least one other time between Thanksgiving and this week. I don’t always take his temperature, because we lost the instant thermometer and he won’t open his mouth or hold still for thirty seconds—a toddler eternity—for an armpit measurement. He took the instant thermometer when I was sick myself—I don’t know, he put it somewhere. (I guess I could get another thermometer, but, then again, maybe you could dig a hole and scream that very helpful advice into it.) I give him medicine when he feels hot. I sometimes test him for COVID. If I had to speculate, I’d say that he has been sick since August, more or less. And so have I, and I’m twenty weeks pregnant, and I’m a physician working in the middle of what the A.A.P. has called a national emergency, and Sam screams “Mommy, Mommy, please lie down, Mommy” very plaintively between coughing fits multiple times every night so that at some point I almost always end up asleep on his pillow until he wakes me by coughing directly into my mouth, and then in the morning I go to the hospital for work, leaving my husband—who currently has bacterial pneumonia himself, no doubt left in the wake of a virus he caught from Sam—to deal with our child.

So now, when the parents of toddlers in the emergency room offer their vague, disjointed stories, I understand them. They are desperate, sleep-deprived ogres, just like me.

Sam, born during a Texas COVID surge in July, 2020, is typical of what some experts are calling an “immunity gap.” He was cared for at home by his father for his first eighteen months, so he avoided the usual viral infections of infancy. When he started day care this year, his immune system was fairly naïve to infections, except for those covered by his vaccines. So, like many kids his age—and their parents, who find themselves exposed to endemic viruses that have mutated just enough to infect us anew—he is getting all of them now. Before COVID, the cohort of kids under age one would be exposed for the first time each winter. This year, a much larger cohort of kids—not just kids in the first winter of life but also older toddlers like Sam—are getting their first infections.

For the millions of children whose important kid work—learning, development, and play—is being interrupted by back-to-back infections, the medical response feels terrifically inadequate. Hospital care prevents many of the sickest children from dying of common infections, and we are lucky to live in a country where widespread vaccination and public-health systems make childhood deaths from illnesses such as diarrhea and pneumonia—the biggest killers of kids worldwide—largely avoidable. For the common RSV, one in two hundred infected kids needs to come to the hospital. (In babies under six months, it’s more like one in fifty.) For the rest, helpful medicines and therapies are sparse. In fact, the A.A.P. makes a blanket recommendation: “cough and cold medicines should not be prescribed, recommended or used for respiratory illnesses in young children.”

The A.A.P. is right, I think. Frustratingly, research shows that cold medicines don’t work well for young kids; they are comparable to placebos. Over-the-counter cough medicines don’t reliably work in adults, either, but a medicine that is marginally effective in a grownup can be worse than useless in a kid, because a kid’s body is smaller and structurally different. Their airways are narrower over all, and their lungs lack structures called pores of Kohn that help us clear secretions from the smallest airways.

Kids may also metabolize drugs differently from adults. Historically, medication dosing for kids has been extrapolated from adult standards, by dividing adult doses in half for kids age six to eleven and in half again for kids age two to five. But differences in physiology mean that an extrapolated dose can produce wildly different levels of the drug in children’s blood. For example, in its report of three infant deaths caused by cold medicine, the C.D.C. found that the babies’ postmortem blood levels of pseudoephedrine were nine to fourteen times higher than those typically found in two-to-twelve-year-olds taking recommended doses. (One of the infants had taken only an O.T.C. cough medicine containing pseudoephedrine; one had taken a prescription version; one had taken both.) Even at safe blood levels, clinical trials may ultimately show that medicines effective in adults are ineffective or harmful in kids. Infants’ cold medicines were removed from the market altogether in 2007; in 2008, labelling on older childrens’ cold medicine was revised to read, “Not for use in children under four.”

Even with the products that remain, it’s still easy to overdose kids. Many combination medicines contain acetaminophen—brand name Tylenol. The toxic dose of acetaminophen, known as the TD50, at which fifty per cent of people would be poisoned, is very close to the effective dose. And, if acetaminophen poisoning isn’t caught in time and treated, an overdose can lead to irreversible liver failure and death. Acetaminophen toxicity is the leading cause of liver transplantation in the United States. It causes fifty-six thousand emergency-room visits and five hundred deaths annually. (Half of these overdoses are accidental; the other half are suicide attempts. Acetaminophen is a particularly popular agent for suicide attempts among youth because it is widely available and parents don’t realize how dangerous it is.)

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