Oxford-AstraZeneca begins a vaccine trial for children. It’s the youngest group yet to be tested.

Oxford University announced Friday it started testing its coronavirus vaccine in children as young as 6 in a move that expands coronavirus vaccine trials to the youngest age group yet.

The Oxford trial will include 300 child volunteers ages 6 to 17, with 240 of them receiving the vaccine co-developed with drugmaker AstraZeneca; the remaining participants will receive a control meningitis vaccine that has been proved safe in children but is expected to mimic side effects of a covid-19 shot, the university said in a statement.