How Close Are We to Another Pandemic?

An outbreak of bird flu has been tearing through the nation’s dairy farms and infecting more and more people. Now there are troubling signs that the United States may be closer to another pandemic, even as President Trump dismantles the country’s public health system. Apoorva Mandavilli, who covers science and global health for The Times, explains how the virus has changed and why our government might be ill-equipped to respond.