Are pediatric trials of coronavirus vaccine candidates underway?

Pfizer Inc. expanded trials of its coronavirus vaccine candidate to include minors in September, adding participants as young as 16, then in October adding patients as young as 12.

Pfizer is the first of multiple companies working on vaccines to announce initial success with its candidate, followed by Moderna Inc. Moderna may start pediatric trials by yearend, Medscape reports. It notes that AstraZeneca plc is already testing its vaccine candidate with 5- to 12-year-olds in the U.K.

Doctors and researchers caution that ensuring a vaccine is safe and effective for children requires care. "Children’s immune systems are very different from adults’, and their immune responses can be different at different ages, from infancy through the teenage years," a doctor at a Hartford children's hospital explains.