Johns Hopkins practices virus simulations as part of is preparedness protocol, with the goal of offering public health experts and policymakers a blueprint of what to do in a pandemic. One of those simulations took place in October 2019, when Toner and a team of researchers launched a coronavirus pandemic simulation in New York, running through various scenarios on how residents, governments and private businesses would hypothetically react to the threat.

One thing that stood out to him: Face coverings are a vital defense to stop the spread of the virus. He believes COVID-19 won’t slow down in the U.S. even as states start to slowly reopen.

“There’s going to be no summertime lull with a big wave in the fall,” he said as part of CNET’s Hacking the Apocalypse series. “It’s clear that we are having a significant resurgence of cases in the summer, and they’ll get bigger. And it’ll keep going until we lock things down again.”