I have some issues with this logic. My oldest daughter spent essentially her whole first 2.5 years in a pretty closed social circle, because she wasn't in day c

I have some issues with this logic. My oldest daughter spent essentially her whole first 2.5 years in a pretty closed social circle, because she wasn't in day care. When she started preschool at age 4, by this logic, shouldn't she have been susceptible to these severe infections? I don't think her situation is all that uncommon. Not every kid went straight to daycare prepandemic. Is there any evidence that children with relatively closed social groups get these severe symptoms when they do get exposed? I don't have a great answer for what is going on, if not this "immunity debt" thing. It just seems a bit flimsy to me. For what it's worth, I've had ER trips for 2 of my toddlers in the past month with rhinovirus/enterovirus, the other pathogen besides RSV that's slamming toddlers currently. They both made pretty quick recoveries with prednisone for one of them and an albuterol nebulizer for the other.