Pfizer vaccine currently has an emergency authorization from the US Food and Drug Administration for those 16 years old and older.
Pfizer is starting the trials first in children between 5 and 11 to determine the appropriate dose. Vaccines will start with 10 micrograms. If that dose is tolerated, the trial will escalate to 20 micrograms and then 30 micrograms. An adult dosage of Pfizer vaccine has 30 micrograms. There is also a 3 microgram option. As with adults, children will be on a two-dose schedule, 21 days apart.
If the 10 microgram dose is tolerated in the 5-11 year old group, the trial will follow the same process for children between the ages of 2 and 5. If tolerated in that age group, next would be vaccine trials for the youngest children, between 6 months and 2 years.
If 10 micrograms is tolerated in the 5-11 age group, the trial will also follow the same process for the 2-5 age group and then for the group of children 6 months to 2 years.
Pfizer has already evaluated the vaccine in 2,259 children between the ages of 12 and 15. The company told CNN the tolerability findings were strong enough among this age group to encourage trials in younger children. They anticipate being able to share the data about the safety and efficacy of the vaccine in the older children age group soon.
Results from the under-12 trial are expected by the end of 2021.