On Oct. 29, 2021, the U.S. FDA authorized the Pfizer pediatric vaccine for children 5 to 11 years old under an Emergency Use Authorization (EUA), meaning the vaccine was proven safe and effective for this age group. This vaccine is a two-dose series, and the doses should be administered three weeks apart. Each dose is 10 mcg, one third of the dose approved for adults. In the FDA analysis, the immune response of the children to the vaccine was comparable to the immune response of the adults. In clinical trials before the emergence of the Omicron variant, the vaccine was found to be 90.7% effective in preventing COVID-19 in children 5 through 11.
See the U.S. FDA fact sheet for more information.