Pfizer Says Vaccine For Kids Ages 5-11 Is 91% Effective

A recent study examined treatment for children aged 5 to 11. Pfizer plans to distribute vaccines as early as next month, potentially allowing some children to be fully vaccinated by the holidays. The FDA is expected to release an initial review of the vaccine's safety later today.

What is expected to be reviewed by the FDA according to the text?

What is the main concern regarding the vaccine mentioned in the text?