Vaccines have been making a lot of headlines over the last five years.

First, because of the remarkable speed with which the COVID vaccine was developed, and more

recently, because of the Trump administration's hostility to vaccines.

I can't think of a better time to have a conversation with today's guest,

Seth Berkeley, who for more than a decade ran the largest vaccination program in the world.

These are amazing technologies that have lifted us up from a situation where people are losing

a third of their kids routinely to a place where people assume you have one child, that child's going to live and be healthy.

Welcome to people I mostly admire with Steve Levitt.

My guess is that you've never heard of Gavi, G-A-V-I, it's spelled, because for an organization

with such a massive impact, it keeps a very low profile. So I started my conversation with

Seth by asking him to just tell me what Gavi does.

Thank you. just tell me what Gavi does. Since Gavi was set up, it's vaccinated over 1.1 billion additional children.

I say additional children because obviously many children get lots of vaccines.

It's credited now with having saved more than

20 million lives, if you include some of the work done in COVID. But it doesn't just do routine vaccines.

It helps build up health systems to be able to deliver these vaccines. And it's responsible for

providing vaccines to about 60% of the world's

children. It also is holding stockpiles of vaccines that are used to prevent epidemics as well,

so lots of different activities working across the world.

It's easy for people to lose sight of how big these numbers are.

Just to reiterate what you said, we're talking about over a billion kids who have been immunized

that wouldn't have been otherwise, and 20 million deaths, which is an incredible number. And so

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