It's the first day of school in many districts in the tri-state area. For the first time in 17 months, all students in Newark will be back inside buildings.

As News 12 has reported, masks are required in all New Jersey schools. Last month, Gov. Phil Murphy issued a mandate requiring all school employees to be fully vaccinated against COVID-19 by Oct. 18 or they must undergo weekly testing.

The return to the classroom comes as the United State surpasses 40 million coronavirus cases since the pandemic began. That's according to new numbers just released from Johns Hopkins.

MORE: Stop the Spread

The latest wave of COVID-19 cases are blamed on the highly contagious delta variant.

The seven-day average of new cases on Labor Day was more than 300% higher than Labor Day of last year. The jump in cases is leading to overcrowded hospitals again.

But this latest wave shows a rise in infections among children.

News 12’s Doug Geed Spoke with pediatrician Dr. John Zaso about the return to the classroom and the spread of the delta variant.

What mask would Dr. Zaso recommend for students?

What lead to the rise in COVID-19 cases among children?

Are those cases mostly caused by asymptomatic spreaders?

Is the delta variant mutating into something stronger?