accine against the new coronavirus, this time to include more young participants. The company said that it's received permission from the Food and Drug Administration to include adolescents aged 12 through 15 in its global COVID-19 vaccine study.US-based Pfizer originally planned for 30,000 participants, but in September expanded that to 44,000 people.Canadian health authorities will start a real-time review of Pfizer's covid vaccine that it is developing with Germany's BioNTech SE.