This fall, North American kids are not alright.
Pediatric hospitals are brimming with an unusually high number of patients who are sick from several different viruses—predominantly RSV, flu, and COVID, but also influenza-like viruses like rhinovirus and enterovirus. Many are at or near capacity, and some are far beyond it, having made room for patient overflow in offices, gift shops, play areas, and parking-lot tents.
Parents, pediatricians, and public health officials alike are asking the same question: How did we get here?
One popular idea that has emerged in the public health community: The surge is due to “immunity debt,” a newly coined term. According to the theory, kids were exposed to fewer germs—COVID and otherwise—over the past three years because of pandemic precautions like masking and social-distancing, and their immune systems atrophied. Now that society has reopened, children are confronting the usual petri dish of viruses with weakened defenses, causing an onslaught of illness—and perhaps greater levels of, and more severe, illness than would have occurred otherwise.
But experts Fortune spoke with say that the theory is unscientific at best and destructive at worst, disagreeing with any argument that COVID precautions damaged immune systems, and emphasizing a wide range of factors resulting in the current “tripledemic.”
What is immunity debt?
When it comes to why kids are getting hit so hard with viruses this fall, immunity debt is “definitely the most popular hypothesis going around,” Dr. Lael Yonker, Harvard Medical System assistant professor of pediatrics at Massachusetts General Hospital, told Fortune.
The general idea is that kids who were born during the pandemic have been protected from viruses that they would have normally been exposed to if they interacted with more people—and that it weakened their defenses.
“These kids are now one year old, two years old, and they haven’t seen…