"This is the part of the horror film where a happy ending seems in sight, but it is obvious to those paying attention that the monster is not dead and that the worst may be yet to come." That's how New York Times columnist Ezra Klein described this moment in the fight against the coronavirus pandemic. We're in a new year, there's a new president, and the record-breaking development of vaccines that work has wounded the monster, but there are deadly battles still ahead. Chief among them: the highly-contagious variants of the COVID-19 virus.

Watch the GZERO World episode: The race to vaccinate