On June 17, 2022, the U.S. FDA authorized the Pfizer pediatric vaccine for children 6 months to 4 years old under an Emergency Use Authorization (EUA), meaning the vaccine was proven safe and effective for this age group. This vaccine is a three-dose series. The first two doses are taken 3 weeks apart and the third dose is taken 8 weeks after the second dose. Each dose is 3 mcg, 1/10 of the dose approved for adults. In clinical trials while the highly contagious Omicron variant was circulating, vaccine efficacy against symptomatic infection was 80%.
See the U.S. FDA fact sheet for more information.