THE LONG ROAD

By the end of January, nearly 100 million people around the world had received COVID-19 vaccines, and more than 1 million were getting shots each day in the United States and China. The effort was lagging in Europe, and staggering global inequities remain. Still, the vaccines, shown in clinical trials to have efficacies of up to 95% against symptomatic disease, have finally given the world the prospect of an escape from COVID-199s long siege. Now, as vaccination campaigns gain speed, a raft of pressing questions have emerged: Does being immunized mean you won9t spread the virus? When will the campaigns begin to curb the pandemic and allow daily life to return to normal? And what do the new variants of SARS-CoV-2, able to spread faster or evade immune responses, mean for the promise of vaccines?