The agency’s new guidelines are wrong, so states have to step up on their own to suppress the coronavirus. By Harold Varmus and Rajiv Shah. Harold Varmus is a former director of the National Institutes of Health. Rajiv Shah is the president of the Rockefeller Foundation. “We were startled and dismayed last week to learn that the Centers for Disease Control and Prevention, in a perplexing series of statements, had altered its testing guidelines to reduce the testing of asymptomatic people for the coronavirus. These changes by the C.D.C. will undermine efforts to end the pandemic, slow the return to normal economic, educational and social activities, and increase the loss of lives. Like other scientists and public health experts, we have argued that more asymptomatic people, not fewer, need to be tested to bring the pandemic under control. Now, in the face of a dysfunctional C.D.C., it’s up to states, other institutions and individuals to act. Understanding what needs to be done requires understanding the different purposes of testing. Much of the current testing is diagnostic. People should get tested if they have symptoms — respiratory distress, loss of smell, fever. There is no argument about this testing, and the altered C.D.C. guidelines do not affect it. But under its revised guidelines, the C.D.C. seeks to dissuade people who are asymptomatic from being tested. Yet this group poses both the greatest threat to pandemic control and the greatest opportunity to bring the pandemic to an end. It is with this group that our country has failed most miserably…”