Pfizer/BioNTech will begin a trial of their COVID-19 vaccine in children under 12 and as young as 6 months old, in hopes of obtaining approval for use in children under 16. Their vaccine is currently approved for people 16 years and older. An initial 144 participant trial will determine the most appropriate dose to administer, and a later 4,500 person trial will look at safety, tolerability and immune response.