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Hi, and welcome to COVID Quickly, a scientific American podcast series.

This is your fast track update on the COVID pandemic.

We bring you up to speed on the science behind the most urgent questions about the virus and the disease.

We de-mystify the research and help you understand what it really means.

I'm Tony Lewis.

I'm Josh Fishman.

And we're a scientific American senior health editors.

Today we're looking at COVID vaccines for the littlest kids, finally, and reasons for getting them.

And why vaccines paradoxically are making it harder to make new antiviral medicines?

At long last, Tonya, kids under five years old are eligible for COVID vaccines.

Can you bring us up to speed on what's happened?

Earlier this month, the FDA authorized the Pfizer and Moderna vaccines for children six months through four or five years old respectively.

The decision came after an FDA advisory panel voted that the benefits of the shots outweighed the risks for these youngest children.

The CDC's own advisory panel also recommended the shots and parents can now start to get their children vaccinated at doctors offices and other sites around the country.

The vaccines for adults got authorized more than a year ago.

Why has it taken so long for little kids?

Well, Josh, you always have to be careful testing any new vaccine or drug in children.

And the risk of severe COVID is greatest in older adults.

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