PINELLAS COUNTY, Fla. — Even before Pfizer's COVID-19 vaccine was authorized for use in teens 12-15 years old, clinical trials were already underway to examine the safety and efficacy of the vaccine in even younger children. The first injections for babies as young as six months to kids up to age 11 were administered back in March, according to the pharmaceutical company. One of the children taking part in the Phase 1 trial is Eloise LaCour, 3.

"We know how incredibly lucky we are to have a healthy child, and we know that there are so many parents out there who are living in fear of the impacts of COVID and the risks associated with that," said Eloise's mother, Angelica LaCour. "So, this was something that we felt like we could give back to our communities, and it's something that would become a reality for other families that we know are in harder positions than we are." 

The LaCours live in the San Francisco Bay area and are participating at the Stanford University trial site. According to Stanford, there are 144 children nationwide taking part in the trial for ages six months to four years old. 

"It's been great," said Chris LaCour, Eloise's father, of the experience so far. "The researchers and the doctors are doing a great job, just making sure that we had all of our questions answered."

Dr. Juan DuMois, a pediatric infectious disease physician with Johns Hopkins All Children's Hospital, said the benefit of vaccinating children this young are twofold: it helps with reaching herd immunity and prevents severe COVID cases in children which, while rare, can be deadly. DuMois said the main difference between trials on young children and other age groups is that researchers typically adjust the dose, trying to determine the lowest amount of vaccine that works best.

"I'll be interested in seeing if the recommended dose of the vaccine is the same as what we're giving to everybody else or if it's going to be a different dose below a certain age," said DuMois. "I'll be interested in looking at the side effect range, and especially to see if the side effects tend to be fewer in younger children than in older children and adults."

The LaCours said Eloise had just a sore arm and headache after her second dose.

"Certainly, we always want to weigh the risks and the benefits," said University of Florida College of Medicine professor and pediatrician Dr. Sonja Rasmussen. "The benefits of the vaccine are much more than what might be the potential risks. We haven't really seen significant risks and side effects."

Eloise will continue checking in with researchers for the next two years. Her parents said their message to others who may be debating whether to vaccinate their children is to consider the evidence.

"There's so much research behind this and people who dedicate their lives to understand viruses and immunology," said Angelica LaCour. "Not knowing the long term impact of the virus but knowing this is a well-tolerated vaccine saving people's lives is something that we need for all of us."

Pfizer has said it expects to submit to the FDA for emergency use authorization for children ages 5-11 in September, and then for those six months-four years old sometime in the fourth quarter.