The FDA is likely to sign off shortly on the Pfizer booster shot for everyone 18 and over, but many cities and states like New York City and California have already made boosters available to all adults. We look at what we do and don't know about who should get boosters and what kind is best.

Guests: Dr. Namandje N. Bumpus, Director of the Department of Pharmacology and Molecular Sciences at Johns Hopkins Medicine; and Axios' Dave Lawler and Russell Contreras.

Credits: Axios Today is produced in partnership with Pushkin Industries. The team includes Niala Boodhoo, Sara Kehaulani Goo, Julia Redpath, Alexandra Botti, Nuria Marquez Martinez, Alex Sugiura, Sabeena Singhani, Lydia McMullen-Laird, David Toledo and Jayk Cherry. Music is composed by Evan Viola. You can reach us at [email protected]. You can text questions, comments and story ideas to Niala as a text or voice memo to 202-918-4893.