If you’re like many parents, you’re probably wondering when children will be able to get the COVID-19 vaccine. The vaccine being administered to healthcare workers and residents of long-term care facilities is the Pfizer vaccine, which is only authorized for people aged 16 and older. Part of the reason kids aren’t likely to get it before higher-risk adults is that they are much less likely to have severe disease if they get it, and they are much less likely to spread the virus than adults.

But the simple explanation is that the vaccines haven’t been tested for children aged 12 and younger. Moderna’s vaccine will begin pediatric clinical trials with kids aged 12 through 17 soon.