If all goes well, sometime in the next six months, one of the many Covid-19 vaccine candidates will receive approval for human use. It will be a day to celebrate. The end of the pandemic will at long last be in sight.

But what happens next? Who gets the first doses? The second batch? How do you actually vaccinate billions and billions of people, quickly and safely? A vaccine isn't the end of the road, as today's guest will tell us, it's more like an off-ramp.

GUEST: Danielle Groen