It was more than two weeks ago that Dr. Peter Hotez, a nationally recognized vaccinologist, put it in plain language. The country’s inability to reach desired vaccination levels for adults and kids 12 and over, Hotez said, will accelerate COVID infection rates — “and the ones who will also pay the price … are the little kids who depend on the adults and adolescents to get vaccinated in order to slow or halt transmission.”

For the first time, perhaps, Los Angeles County has begun to see that story play out. In a briefing for the county’s Board of Supervisors this week, public health director Dr. Barbara Ferrer presented statistics that indicate a fivefold increase in a month of COVID case rates for county residents under 12 years old.

The raw numbers are low relative to county residents age 12 to 49 — in the two-week period ending July 18, there were 89 cases per 100,000 people age 0 to 4, and 112 cases per 100,000 age 5 to 11 — and no pediatric COVID deaths were recorded in the county for the period from June 18 to July 18. But the spike in case rates among the very young is precisely what many health experts feared when the county lifted mask restrictions and mostly followed the state’s lead in a broad June 15 reopening.