About a year into the global pandemic, as the worldwide death toll exceeds a dizzying 2.5 million—more than half a million in the United States alone—hope has arrived in the form of multiple vaccines created in record time that have shown impressive success in preventing COVID-19. 

“What all the vaccines have been is very highly protective against severe disease, hospitalization, and death,” says William Moss, executive director of the International Vaccine Access Center at Johns Hopkins Bloomberg School of Public Health. That, he says, is the most important success story of COVID-19 vaccines and will help bring this brutal pandemic under control.

With the number of vaccinated individuals growing daily, many wonder: What previously risky activities, such as meeting up