Moderna has begun testing its COVID-19 vaccine in children as young as 6 months old and up to 11 years old, the company announced. 

The trial includes healthy children in the U.S. and Canada and will be conducted in two parts, according to a statement from the company. In the first stage, the company will test how the participants respond to different dose levels of the vaccine. Children older than 2 years old may receive 50 or 100 micrograms of vaccine per dose, while children younger than 2 may receive 25, 50 or 100 micrograms. Each child will receive two doses in total, with each dose given 28 days apart, the same spacing as the shots given to adults.