Why more kids are not included in COVID-19 vaccine studies

In this photo provided by Cincinnati Children's Hospital Medical Center, clinical research coordinator Tammy Lewis-McCauley administers an injection to Katelyn Evans, a trial participant, as part of the hospital's clinical trial of Pfizer's COVID-19 vaccine. (Uncredited, Cincinnati Children’s Hospital Medical Center)

The race continues to release a COVID-19 vaccine, but it seems as though most of the trials happening right now are focused on adults. But kids can be infected too, so why aren’t more children being included in the research?

“We well recognize that during this pandemic most of the problems are in adults and children are not immune, but they are more resilient, “said Frank Esper, an infectious disease specialist with Cleveland Clinic Children’s. “Children can still get infected and still get very sick but thankfully not nearly in the numbers that we see in adults.”

Recommended Videos



Esper said it’s not uncommon for drug trials to focus on adults first. That’s because there are more layers of protection required for kids, which can be time-consuming.

Another reason is that children are still growing, so trials have to be separated by several age groups, and that means more participants are needed. However, with adults, they can categorize them more easily.

Lastly, he said it’s harder to enroll children in research studies. You can enroll many adults fairly quickly into a vaccine trial, but it takes much longer to get enough children. And time is of the essence when it comes to developing a COVID-19 vaccine.

“Children’s immune systems are growing up just like they are, so there is a big difference between a 2-year-old, a 20-year-old, and a 92-year-old in their immune system,” Esper said. “So, you can’t say all children are the same. You actually have to test specific age groups of children.”

Esper said we won’t be able to fully control the pandemic until there’s a vaccine for all ages. Right now, adults are the priority, but he’s confident studies involving children are on the way.