The Centers for Disease Control and Prevention was created to stop deadly pathogens. But 2020 has been a disaster for the CDC. The agency's response to the worst public health crisis in a century - the coronavirus pandemic - has been marked by technical blunders and botched messaging. The agency has endured false accusations and interference by Trump administration political appointees. Worst of all, the CDC has experienced a loss of institutional credibility at a time when the nation desperately needs to know whom to trust. The stumbles started early in the pandemic, with the botched rollout of test kits suspected of being contaminated at a CDC lab in late January. But the agency's most chronic problem has been the inability to speak directly and persuasively to the American public. That's because it has been muzzled ... by political operatives. White House officials have pressured the CDC to change guidance over the last several months to align the guidelines more closely with the administration's message that the pandemic is under control, federal health officials have said. Those actions include revised CDC guidance on mask-wearing and the reopening of religious institutions and schools. "Every big public health response has two components: the public health emergency and the political emergency," said a CDC epidemiologist who spoke on the condition of anonymity out of fear of retaliation. "I never would have expected the level of political interference we're seeing now. It's so sad."