It’s time for Biden to make the case for vaccine requirements

But vaccinated Americans should also care whether people around them have gotten the shot. Here’s why: If everyone around them is also vaccinated, the chance of them being infected and then contracting covid-19 is virtually nil. On the other hand, if they’re in multiple settings every day where they are constantly surrounded by unvaccinated people, the risk of getting infected increases. Risk is additive, so the more unvaccinated people they’re exposed to, and the higher the rate of coronavirus in their community, the higher the risk.