Seven-year-old Gael Coreas on Wednesday became one of the first kids under age 11 to be vaccinated against COVID-19, as the U.S. began inoculating children aged 5 to 11 one day after the CDC recommended the Pfizer/BioNTech shot for broad use in that group – opening up eligibility to some 28 million kids.

It’s a third of the strength of the dose given to adolescents and adults, and offers protection from the highly contagious Delta variant.

For many, it couldn’t come soon enough.

Since the start of the pandemic, nearly 2 million kids in the U.S. under age 12 have been diagnosed with COVID, says pediatric emergency doctor Matthew Harris.

"8,400 of them have been hospitalized. So there's an urgent need for vaccination."

The Pfizer vaccine is shown to be more than 90% effective at preventing symptomatic infection in children, bringing with it the hope of fewer quarantines or school closures and more normal activities and freedoms.

That’s a relief for New Jersey mom Jojo Doble, whose two young children have not seen their grandfather, who is immunocompromised, for two years.

“It'll make life that much easier to be able to take the kids places to not feel so worried about, 'Do we have a mask, do we not have a mask? Can we be around these friends and their kids? Can we be around my parents? Can we be around our neighbors?' And not all have to stand outside around a fire pit or with several layers on now that it's getting cold.”

Still, it remains unclear how many parents will jump at the chance. Even many who have been vaccinated themselves are more divided over whether to vaccinate their own younger children, given that severe COVID is much less common for them. Dr. Harris empathizes, but calls Pfizer’s research “impressive.”

“I am a parent of school-aged children, of 7-year-old twins, and I recognize that this is a difficult choice for parents to make. But for me, the calculus is simple. This is the easiest way I can keep my kids safe.”

California has mandated school-age children get vaccinated once their age group is eligible, a measure being considered in New York and Washington state.