Three different vaccines to protect against COVID-19 have been either approved or authorized for emergency use in the U.S. And now the conversation has turned to booster doses for all three.Booster shots are nothing new. After all, a flu "booster" is what is encouraged each and every year. When it comes to COVID-19, however, the back and forth and disconnect between the different government agencies may have left some confusion about who does and doesn't need a booster.After all, COVID vaccine studies show that even after a few months, efficacy is still higher than the original goal for the vaccine.On this week's episode, Ellie Murray, ScD, assistant professor of epidemiology at Boston University School of Public Health, joins us to help answer the question, do I really need another shot?