Photo by Paul Bersebach/MediaNews Group/Orange County Register via Getty Images
Photo by Paul Bersebach/MediaNews Group/Orange County Register via Getty Images

“We have never seen that in this pandemic.”

Children now comprise 25% of new cases of COVID-19 in Arizona’s largest county, health officials said Monday.

Maricopa County, home to 4.5 million of the state’s residents, has seen a sharp increase in COVID-19 cases among children since schools reopened this fall. The Pfizer vaccine is currently only open under emergency use authorization to those 12 and older.

Now, one in six new cases being reported are in children under the age of 12, according to Dr. Rebecca Sunenshine, the county’s medical director.

“We have never seen that in this pandemic,” Sunenshine said Monday.

The new numbers come as Arizona Gov. Doug Ducey has attempted to block public school districts from requiring masks, even threatening to withhold federal funding from any districts that do. Many districts have moved forward with mandating masks regardless.

As of Wednesday, the state had reported over 1 million cases of COVID-19, with over 600,000 cases in Maricopa County. Nearly every school district in the county was showing a high level of community transmission, according to the Maricopa County Department of Public Health.

The last time the state saw similar numbers was during Thanksgiving of last year, before the pandemic’s numbers peaked in January. Cases began declining once the vaccine rollout began throughout the state, according to Maricopa County Public Health Executive Director Marcy Flanagan.

As of Tuesday, nearly 52% of adults in Maricopa County had received at least one dose of the vaccine.

“We know that we’re seeing this increase even with the vaccine available,” Flanagan said.

What’s Driving The Increase?

The original strain of COVID-19 did not infect children as much as it affected adolescents and older people, but the Delta variant is twice as contagious and more likely to infect children, Sunenshine said Monday.

Cases also shot up dramatically when children started returning to school this semester.

Sunenshine pointed to the fact that potential mitigation strategies, like masks and social distancing, are not necessarily being put in place in school, contributing to spread.

Schools that do not have a mask requirement are twice as likely to have an outbreak as schools that do require them, she said.

The county was able to keep spread among school-aged children down during the holiday season, when the spread of COVID-19 was at its peak, because of mitigation strategies that were in place like masks and hybrid schedules that allowed for fewer students to be in class at the same time and more ability to social distance.

According to data from the county, there were 166 ongoing school outbreaks in Maricopa County as of last Thursday, three times the number of school outbreaks compared to the last peak in February.

Original estimates said children under the age of 12 would be eligible for vaccination by September, but the timing for an FDA review has been pushed back. The county estimates that an emergency use authorization for the vaccine to be available for children likely won’t come until the end of the calendar year.

“I know I personally will sleep a lot better when these kids can get vaccinated because we know they need to be in school, and we want to give them as much protection as we can,” Sunenshine said.