The fall Covid-19 booster campaign will be upon us soon and how well the new Omicron-specific boosters will work may depend on a phenomenon called “original antigenic sin.”  Since people have been infected, vaccinated, and boosted, people’s immune systems are on different playing fields and your first exposure may play a bigger part in future immune responses.  Carolyn Johnson, science reporter at the Washington Post, joins us for what to know.See omnystudio.com/listener for privacy information.