Charley, Ellie and Sydney — 7, 8 and 10 years old, respectively — all received their vaccine over the summer during a large trial in Colorado.

“The worst thing is that it hurts,” Ellie said. “And the best thing is it keeps you safe.”

Their parents, Dr. Rachel Brewer, a sports medicine physician at Rocky Mountain Hospital for Children and Dr. JP Brewer, ER physician at Rose Medical Center said the decision to enter the trial made sense.

Watch the Fox31 story

Learn more about the vaccine at Rocky Mountain Hospital for Children

Find registration information throughout Colorado for the Pfizer vaccine for kids 5-11