AURORA, Colo. (CBS4)- As Colorado starts to loosen COVID-19 restrictions, there is still work being done to ensure the youngest children are protected. Moderna is in the middle of their vaccine trial for infants to those under five years old and researchers at the Children's Hospital and the University of Colorado Anschutz campus are playing a major role in that progress.

Eight-month-old Lily and eight-month-old Arlo, 2-year-old Georgia and her brother 4-year-old Wyatt are some of the youngest participants in the Colorado Study.

"She was one of the smallest of the little littles able to join," Lily's mom Krystal Atwood said.

Each child has had their first and second shot, whether it was the vaccine they won't know for some time still.

"How has it been miss?" Atwood asked Lily, "What do you think? You're still happy, you're still strong," she said.

Each of the families enrolled at different times starting at the end of 2021, today they are all at different stages of the study.

"I'll hold your chin... one, two, three, good job sweetie," Clinical Trials Senior research Nurse, Tori Rutherford said while collecting a nasal swab from Georgia.

Researchers will follow the health of each child for more than a year, with the families coming in for multiple visits during that time.

Using an app on their phones, they can also track any changes or concerns from parents.

"It just asks what temps she has, has it been checked, does she have any reaction," Atwood said.

While some may feel like COVID-19 is coming to an end, Jane Ott says for those with family left unprotected, like her children, it is far from over.

"I feel like they are kind of the forgotten group. Where people are thinking a lot of adults are all vaccinated and if they do get COVID, it's mild, while what about the children that are not vaccinated."

Having an opportunity to change that, Nicole Poole says she jumped at the chance to volunteer.

"Doing these little things being able to get into the study in the first place was at least something I felt like something I can do in a state of feeling like you can't do much," she said.

That protection is their top priority, but Krystal Atwood says the broad impact was part of her decision.

"There's a lot of kiddos that we don't think about that have cancer or have autoimmune deficiencies. If you're getting your kid vaccinated especially when masks are coming off in schools, you're helping to protect those kids," she said.

While being part of the trial is a way to help, it's also a chance to change how these families will look back on the pandemic and their role in it.

"This whole experience of living through a pandemic has been so unusual and just the opportunity to contribute to science to this scale is something I never thought we would be a part of," Ott said.

Right now there's no clear timeline for when the FDA might approve of a vaccine for this age group.