Moderna said Tuesday its COVID-19 vaccine strongly protects kids as young as 12, a step that could put the shot on track to become the second option for that age group in the U.S. ... But earlier this month, the U.S. and Canada authorized another vaccine — the shot made by Pfizer and BioNTech — to be used starting at age 12. Moderna aims to be next in line, saying it will submit its teen data to the FDA and other global regulators early next month.