The surge in coronavirus cases around the world, led by US states like Florida and Texas, serves as a reminder of the urgent need for more testing. But those who can get a test must sometimes wait days for the results. As part of our regular series discussing the pandemic and as a special podcast in The World's feed, reporter Elana Gordon moderated a discussion with epidemiologist Dr. Michael Mina from Harvard's T.H. Chan School of Public Health on the latest advances in COVID-19 testing.