Coronaviruses are not new but the new COVID-19 causes more severe symptoms and led to a global pandemic, in large part because it can be spread asymptomatically. In March 2020 the US became the epicenter of the pandemic and remained the hotbed until the vaccines became available. Dr. Monica Gandhi explains how the vaccines work and provides details on the efficacy of the current vaccines. Series: "Mini Medical School for the Public" [Health and Medicine] [Show ID: 37141]