Pfizer vaccine shown to be 100 percent effective on children as young as 12

Tested on children as young as 12, Pfizer’s vaccine has been shown to be 100 percent effective – a promising development for millions of families and the push to reopen schools. But the coast-to-coast surge in COVID-19 cases and hospitalizations is fueling mounting concern from health officials. NBC’s Miguel Almaguer reports for TODAY.March 31, 2021