Latest w/ @EmilyZFeng: COVID-19 patients who've retested positive and asymptomatic carriers are now the focus of China's prevention efforts, but the science here remains unclear. As the U.S. takes over #1 case count from China, here's why we should care:https://t.co/JETkGqnCsN

— Amy Cheng ⛸ (@Amy_23_Cheng) March 27, 2020