On June 18, the CDC backed the FDA's authorizations for Pfizer's and Moderna's vaccines for children under 5, offering protection against COVID-19 for about 19 million infants and preschoolers in the U.S.
Here are four things to know:
1. More than 100 hospitals, pediatrician's offices and pop-up clinics have 10 million doses of both vaccines and will inoculate children 5 and younger nationwide this week.
2. Moderna's two-dose, 25-microgram vaccine is for 6-month- to 5-year-olds. Pfizer's three-shot, 3-microgram vaccine is for 6-month- to 4-year-olds.
3. Pfizer's vaccine has an 80 percent efficacy rate. The Moderna vaccine has a 51 percent efficacy rate for children 6 to 23 months old, and a 37 percent efficacy rate for 2- to 5-year-olds.
4. In clinical studies, both companies reported side effects comparable to reactions among older populations.