CINCINNATI — Cincinnati Children's Hospital is among four U.S. locations participating in the first phase of Pfizer-BioNTech's trial for testing its COVID-19 vaccine on children ages 5 to 11 this week. 

Eight children from the Cincinnati-area are participating in the trial, Dr. Robert Frenck , the director of the National Institutes of Health-funded Vaccine and Treatment Evaluation Unit and Gamble Program for Clinical Studies at the medical center, told Spectrum News 1.

Early Tuesday, Pfizer announced its preliminary data shows its vaccine was safe and effective on children as young as 12. In a study of 2,260 U.S. volunteers ages 12 to 15, no cases of COVID-19 were reported among the adolescents who were fully vaccinated, compared to the 18 participants in the group who received dummy shots, according to Pfizer. 

The company said the side effects for kids were about the same as adults, including fever, chills and fatigue.

While it's the same vaccine that millions of adults have been received, it may be given to children at a lower dose. Frenck explained the first phase is for “dose-ranging,” which is the process of finding the appropriate dosage to give to individuals. 

"Last year when we started the adult trial, we did a dose-ranging. We found a dose and went forward with that. Now as we're starting with children, we're doing the same thing. We're starting back at the lower dose we did with adults and then working up to try to find the appropriate dose for the children," Frenck said.

The trial will move next to 2 to 4 year olds. The final part of the trial is expected to include 6-month-old infants to 2 year olds. 

"What we're doing in this first phase is just to find a dose and it may be the 10 micrograms, which is the low dose we're starting with may be enough for the kids because their immune system works really well," Frenck said.

Cincinnati Children's has played a pivotal role for COVID-19 vaccine trials with more than 1,200 participants involved since last year. 

Pfizer is the only authorized COVID-19 vaccine for ages 16 and 17 year olds. Cincinnati Children's is also participating in Moderna's trial involving kids. The company started with 12 to 17 year olds last year, and announced last week it is starting to test children 12 and younger. 

The hospital reported more than 500 families have expressed interest in participating. Some hospitals chosen in other states began administering shots for the trial late last week, like North Carolina. 

"I have a colleague that enrolled three children in North Carolina. We've enrolled three here so far. Everybody has been doing great. One of my colleagues in North Carolina said their participants went out and played soccer over the weekend," Frenck said.

Although children represent 13% of COVID-19 cases nationwide, more than 3 million children have been infected with COVID-19, around 13,500 were hospitalized and 268 have died, according to American Academy of Pediatrics. 

Ohio became one of the first states to expand eligibility to everyone 16-years-old and older last week after Gov. Mike DeWine gave vaccine providers the green light to start filling appointments due to increased cancellations. The state received its largest shipment to date this week, with more than 571,000 first doses of all three approved vaccines. 

Despite the expansion, DeWine warned Monday the state is seeing an uptick in cases primarily in the 20 to 30 age group. As of Monday, the state has reported 1,015,577 cases, 52,968 hospitalizations and 18,609 deaths. 

For more information on how to get involved in Cincinnati Children's COVID-19 vaccine trials, click here

Sophia Constantine contributed to this story.