The Impact of Vaccines and Behavior on US Cumulative Deaths from COVID-19

We estimate that the combination of changes in behavior to slow the spread of COVID-19 and the delivery of vaccines to a substantial majority of the American population by mid-2021 saved close to 800,000 American lives relative to what would have occurred had vaccines not been developed. We argue that the duration and magnitude of this behavioral response—and thus its overall success in delaying infections—came as a surprise, relative to both our historical experience with pandemic influenza and to model-based projections based on that experience. Thus, we take from our experience with COVID-19 over the past four years the important public health lesson that behavior change can be a powerful force for slowing the spread of a dangerous infectious respiratory disease for a long time. At the same time, these behavioral changes to slow the spread of COVID-19 came at a tremendous economic, social, and human cost. To avoid similar pain from mitigation in the next pandemic, we argue that we need to make investments now not only in vaccine development, but also in data infrastructure so that we can precisely target behavior-oriented mitigation efforts to minimize their economic and social impacts in the next pandemic.