I appreciate that. Like I said, I do believe they are effective at preventing their target illness. I would much rather every child got these vaccines than no child got them, but I'm interested in whether we're making the right assessments at the margins.

Also, it's not clear how much of the decline to attribute to vaccines since the trend predates these vaccines.

I think it's misguided to conclude we're under vaccinating just because there are some occurrences of the disease. We have to know how to weigh those instances of infection against whatever the costs would be to vaccinate enough kids to have prevented it.