evidence: Nearly 800,000 Americans have died so far during the U.S. COVID-19 pandemic, with more than half those deaths occurring during 2021.1 One year into the U.S. vaccination effort, much attention has focused on the stubborn persistence of the pandemic, which has been fueled by new, more- transmissible variants and the millions of Americans who have not gotten their shots. However, the positive impact of the rapid development and deployment of highly effective vaccines — the reduction in deaths and hospitalizations — has been less obvious. [...] The U.S. vaccination program campaign has profoundly altered the trajectory of the COVID-19 pandemic, preventing nearly 1.1 million deaths. Even with only about 60 percent of Americans vaccinated to date, the nation has dodged a massive wave of COVID-19 deaths that would have started as the Delta variant took hold in August 2021. Because of Delta’s rapid and nationwide spread, deaths due to COVID-19 would have far exceeded all previous peaks.