Absence of human contact is associated with declines in cognitive function. But as the COVID-19 pandemic brings concerns about the potential harms of isolation to the fore, researchers are still hunting for concrete evidence of a causal role as well as possible mechanisms.

As communities and businesses reopen amidst the pandemic, masks—in addition to other social distancing measures—are crucial for preventing new outbreaks.

Not all masks are created equal, and how they are worn makes a difference too.

Social distancing measures prevented millions of COVID-19–related deaths around the world, according to a handful of studies, but it’s hard to quantify the effects with certainty.

Social distancing measures are based on limited data. As much of the world remains stuck in lockdown, researchers are trying to measure the benefits.