Embedded Player With booster shots on the horizon for some people, one of the biggest questions is: Am I still protected against COVID-19 if I've only had two doses of the vaccine? As science correspondent Michaeleen Doucleff reports, the answer is...complicated.

Read more of Michaeleen's reporting on COVID immunity: https://n.pr/2XIQ6KX

Reach the show by emailing shortwave@npr.org.