In a landmark move in the battle against the deadly coronavirus, the US has approved Pfizer's COVID-19 vaccine for its emergency use in children aged between 12-15 years. Pfizer's vaccine is being used in multiple countries for teens as young as 16, and Canada recently became the first to expand use to 12 and up. Children are far less likely than adults to get seriously ill from COVID-19 yet they still have been hard-hit by the pandemic. Watch this report.