Because children’s bodies are so different from adult bodies, it’s important to thoroughly test the COVID-19 vaccines on them as well. Children’s immune systems respond differently so we won’t know the safety and efficacy of an adult vaccine until we do trials in children.
The American Academy of Pediatrics (AAP) is urging federal agencies to support timely, but safe, development of COVID-19 vaccines for children, to help understand any potential unique immune responses and/or safety concerns in children.
You can expect initial testing to occur in teenagers and once the safety of a vaccine is established in older children, testing will move to younger age groups. Much like the trials performed in adults, these will take months and the data will have to be analyzed.
As of January 1, 2021, Pfizer and Moderna were conducting phase 3 clinical trials on their vaccines with children as young as 12 years old.