While there are three safe and effective vaccines authorized in the U.S. to protect against COVID-19, there’s still a lot about vaccine immunity that researchers are still trying to figure out. One question has to do with the millions in the U.S. who have been infected with SARS-CoV-2 and recovered. Do they have natural immunity because of their infection, and if so, do they still need to get vaccinated? How much additional protection do the vaccines give them?
