Senator Doug Jones (D-AL) asks a question during a U.S. Senate Senate Health, Education, Labor, and Pensions Committee Hearing to examine COVID-19, focusing on an update on the federal response at the U.S. Capitol in Washington, D.C., U.S., September 23, 2020. Alex Edelman/Pool via REUTERS

Anthony Fauci, MD, Director, National Institute of Allergy and Infectious Diseases, National Institutes of Health, listens to questioning as he testifies during a U.S. Senate Senate Health, Education, Labor, and Pensions Committee Hearing to examine COVID-19, focusing on an update on the federal response at the U.S. Capitol in Washington, D.C., U.S., September 23, 2020. Alex Edelman/Pool via REUTERS

ADM Brett Giroir, MD, Assistant Secretary For Health, United States Department of Health and Human Services, testifies during a U.S. Senate Senate Health, Education, Labor, and Pensions Committee Hearing to examine COVID-19, focusing on an update on the federal response at the U.S. Capitol in Washington, D.C., U.S., September 23, 2020. Alex Edelman/Pool via REUTERS

Robert Redfield, MD, Director, United States Centers for Disease Control and Prevention, testifies during a U.S. Senate Senate Health, Education, Labor, and Pensions Committee Hearing to examine COVID-19, focusing on an update on the federal response at the U.S. Capitol in Washington, D.C., U.S., September 23, 2020. Alex Edelman/Pool via REUTERS

U.S. Senator Chris Murphy (D-CT) speaks during a U.S. Senate Senate Health, Education, Labor, and Pensions Committee hearing to examine COVID-19, focusing on an update on the federal response at the U.S. Capitol in Washington, D.C., U.S., September 23, 2020. Alex Edelman/Pool via REUTERS

U.S. Senator Susan Collins (R-ME) speaks during a U.S. Senate Senate Health, Education, Labor, and Pensions Committee hearing to examine COVID-19, focusing on an update on the federal response at the U.S. Capitol in Washington, D.C., U.S., September 23, 2020. Alex Edelman/Pool via REUTERS

FDA Commissioner Stephen Hahn testifies before the U.S. Senate Senate Health, Education, Labor, and Pensions Committee at a hearing to examine COVID-19, focusing on an update on the federal response at the U.S. Capitol in Washington, D.C., U.S., September 23, 2020. Alex Edelman/Pool via REUTERS

FDA Commissioner Stephen Hahn testifies before the U.S. Senate Senate Health, Education, Labor, and Pensions Committee at a hearing to examine COVID-19, focusing on an update on the federal response at the U.S. Capitol in Washington, D.C., U.S., September 23, 2020. Alex Edelman/Pool via REUTERS

FDA Commissioner Stephen Hahn attends a U.S. Senate Senate Health, Education, Labor, and Pensions Committee hearing to examine COVID-19, focusing on an update on the federal response at the U.S. Capitol in Washington, D.C., U.S., September 23, 2020. Alex Edelman/Pool via REUTERS

FDA Commissioner Stephen Hahn testifies before the U.S. Senate Senate Health, Education, Labor, and Pensions Committee at a hearing to examine COVID-19, focusing on an update on the federal response at the U.S. Capitol in Washington, D.C., U.S., September 23, 2020. Alex Edelman/Pool via REUTERS

ADM Brett Giroir, MD, Assistant Secretary For Health, United States Department of Health and Human Services, testifies before a U.S. Senate Senate Health, Education, Labor, and Pensions Committee at a hearing to examine COVID-19, focusing on an update on the federal response at the U.S. Capitol in Washington, D.C., U.S., September 23, 2020. Graeme Jennings/Pool via REUTERS

ADM Brett Giroir, MD, Assistant Secretary For Health, United States Department of Health and Human Services, testifies before a U.S. Senate Senate Health, Education, Labor, and Pensions Committee at a hearing to examine COVID-19, focusing on an update on the federal response at the U.S. Capitol in Washington, D.C., U.S., September 23, 2020. Graeme Jennings/Pool via REUTERS

U.S. Senator Richard Burr (R-NC) speaks during a U.S. Senate Senate Health, Education, Labor, and Pensions Committee hearing to examine COVID-19, focusing on an update on the federal response at the U.S. Capitol in Washington, D.C., U.S., September 23, 2020. Graeme Jennings/Pool via REUTERS

FDA Commissioner Stephen Hahn testifies before a U.S. Senate Senate Health, Education, Labor, and Pensions Committee at a hearing to examine COVID-19, focusing on an update on the federal response at the U.S. Capitol in Washington, D.C., U.S., September 23, 2020. Graeme Jennings/Pool via REUTERS

FDA Commissioner Stephen Hahn testifies before a U.S. Senate Senate Health, Education, Labor, and Pensions Committee at a hearing to examine COVID-19, focusing on an update on the federal response at the U.S. Capitol in Washington, D.C., U.S., September 23, 2020. Graeme Jennings/Pool via REUTERS

FDA Commissioner Stephen Hahn testifies before a U.S. Senate Senate Health, Education, Labor, and Pensions Committee at a hearing to examine COVID-19, focusing on an update on the federal response at the U.S. Capitol in Washington, D.C., U.S., September 23, 2020. Graeme Jennings/Pool via REUTERS

FDA Commissioner Stephen Hahn testifies before a U.S. Senate Senate Health, Education, Labor, and Pensions Committee at a hearing to examine COVID-19, focusing on an update on the federal response at the U.S. Capitol in Washington, D.C., U.S., September 23, 2020. Graeme Jennings/Pool via REUTERS

Anthony Fauci, MD, Director, National Institute of Allergy and Infectious Diseases, National Institutes of Health, reacts during a U.S. Senate Senate Health, Education, Labor, and Pensions Committee Hearing to examine COVID-19, focusing on an update on the federal response at the U.S. Capitol in Washington, D.C., U.S., September 23, 2020. Graeme Jennings/Pool via REUTERS

Anthony Fauci, MD, Director, National Institute of Allergy and Infectious Diseases, National Institutes of Health, reacts during a U.S. Senate Senate Health, Education, Labor, and Pensions Committee Hearing to examine COVID-19, focusing on an update on the federal response at the U.S. Capitol in Washington, D.C., U.S., September 23, 2020. Graeme Jennings/Pool via REUTERS

Anthony Fauci, MD, Director, National Institute of Allergy and Infectious Diseases, National Institutes of Health, reacts during a U.S. Senate Senate Health, Education, Labor, and Pensions Committee Hearing to examine COVID-19, focusing on an update on the federal response at the U.S. Capitol in Washington, D.C., U.S., September 23, 2020. Graeme Jennings/Pool via REUTERS

Anthony Fauci, MD, Director, National Institute of Allergy and Infectious Diseases, National Institutes of Health, testifies during a U.S. Senate Senate Health, Education, Labor, and Pensions Committee Hearing to examine COVID-19, focusing on an update on the federal response at the U.S. Capitol in Washington, D.C., U.S., September 23, 2020. Graeme Jennings/Pool via REUTERS

Anthony Fauci, MD, Director, National Institute of Allergy and Infectious Diseases, National Institutes of Health, testifies during a U.S. Senate Senate Health, Education, Labor, and Pensions Committee Hearing to examine COVID-19, focusing on an update on the federal response at the U.S. Capitol in Washington, D.C., U.S., September 23, 2020. Graeme Jennings/Pool via REUTERS

Anthony Fauci, MD, Director, National Institute of Allergy and Infectious Diseases, National Institutes of Health, testifies during a U.S. Senate Senate Health, Education, Labor, and Pensions Committee Hearing to examine COVID-19, focusing on an update on the federal response at the U.S. Capitol in Washington, D.C., U.S., September 23, 2020. Graeme Jennings/Pool via REUTERS

Anthony Fauci, MD, Director, National Institute of Allergy and Infectious Diseases, National Institutes of Health, testifies during a U.S. Senate Senate Health, Education, Labor, and Pensions Committee Hearing to examine COVID-19, focusing on an update on the federal response at the U.S. Capitol in Washington, D.C., U.S., September 23, 2020. Graeme Jennings/Pool via REUTERS

Anthony Fauci, MD, Director, National Institute of Allergy and Infectious Diseases, National Institutes of Health, testifies during a U.S. Senate Senate Health, Education, Labor, and Pensions Committee Hearing to examine COVID-19, focusing on an update on the federal response at the U.S. Capitol in Washington, D.C., U.S., September 23, 2020. Graeme Jennings/Pool via REUTERS

U.S. Senator Rand Paul (R-KY) speaks during a U.S. Senate Senate Health, Education, Labor, and Pensions Committee Hearing to examine COVID-19, focusing on an update on the federal response at the U.S. Capitol in Washington, D.C., U.S., September 23, 2020. Alex Edelman/Pool via REUTERS

U.S. Senator Rand Paul (R-KY) looks on during a U.S. Senate Senate Health, Education, Labor, and Pensions Committee Hearing to examine COVID-19, focusing on an update on the federal response at the U.S. Capitol in Washington, D.C., U.S., September 23, 2020. Alex Edelman/Pool via REUTERS

Robert Redfield, MD, Director, United States Centers for Disease Control and Prevention, testifies during a U.S. Senate Senate Health, Education, Labor, and Pensions Committee Hearing to examine COVID-19, focusing on an update on the federal response at the U.S. Capitol in Washington, D.C., U.S., September 23, 2020. Alex Edelman/Pool via REUTERS

Robert Redfield, MD, Director, United States Centers for Disease Control and Prevention, testifies during a U.S. Senate Senate Health, Education, Labor, and Pensions Committee Hearing to examine COVID-19, focusing on an update on the federal response at the U.S. Capitol in Washington, D.C., U.S., September 23, 2020. Alex Edelman/Pool via REUTERS

Robert Redfield, MD, Director, United States Centers for Disease Control and Prevention, testifies during a U.S. Senate Senate Health, Education, Labor, and Pensions Committee Hearing to examine COVID-19, focusing on an update on the federal response at the U.S. Capitol in Washington, D.C., U.S., September 23, 2020. Alex Edelman/Pool via REUTERS

Robert Redfield, MD, Director, United States Centers for Disease Control and Prevention, testifies during a U.S. Senate Senate Health, Education, Labor, and Pensions Committee Hearing to examine COVID-19, focusing on an update on the federal response at the U.S. Capitol in Washington, D.C., U.S., September 23, 2020. Alex Edelman/Pool via REUTERS

Robert Redfield, MD, Director, United States Centers for Disease Control and Prevention, testifies during a U.S. Senate Senate Health, Education, Labor, and Pensions Committee Hearing to examine COVID-19, focusing on an update on the federal response at the U.S. Capitol in Washington, D.C., U.S., September 23, 2020. Alex Edelman/Pool via REUTERS

Robert Redfield, MD, Director, United States Centers for Disease Control and Prevention, testifies during a U.S. Senate Senate Health, Education, Labor, and Pensions Committee Hearing to examine COVID-19, focusing on an update on the federal response at the U.S. Capitol in Washington, D.C., U.S., September 23, 2020. Alex Edelman/Pool via REUTERS

Robert Redfield, MD, Director, United States Centers for Disease Control and Prevention, testifies during a U.S. Senate Senate Health, Education, Labor, and Pensions Committee Hearing to examine COVID-19, focusing on an update on the federal response at the U.S. Capitol in Washington, D.C., U.S., September 23, 2020. Alex Edelman/Pool via REUTERS

Robert Redfield, MD, Director, United States Centers for Disease Control and Prevention, testifies during a U.S. Senate Senate Health, Education, Labor, and Pensions Committee Hearing to examine COVID-19, focusing on an update on the federal response at the U.S. Capitol in Washington, D.C., U.S., September 23, 2020. Alex Edelman/Pool via REUTERS

Committee Chairman Senator Lamar Alexander (R-TN), speaks during a U.S. Senate Senate Health, Education, Labor, and Pensions Committee Hearing to examine COVID-19, focusing on an update on the federal response at the U.S. Capitol in Washington, D.C., U.S., September 23, 2020. Graeme Jennings/Pool via REUTERS

Robert Redfield, MD, Director, United States Centers for Disease Control and Prevention, testifies during a U.S. Senate Senate Health, Education, Labor, and Pensions Committee Hearing to examine COVID-19, focusing on an update on the federal response at the U.S. Capitol in Washington, D.C., U.S., September 23, 2020. Graeme Jennings/Pool via REUTERS

Robert Redfield, MD, Director, United States Centers for Disease Control and Prevention, testifies during a U.S. Senate Senate Health, Education, Labor, and Pensions Committee Hearing to examine COVID-19, focusing on an update on the federal response at the U.S. Capitol in Washington, D.C., U.S., September 23, 2020. Graeme Jennings/Pool via REUTERS

Anthony Fauci, MD, Director, National Institute of Allergy and Infectious Diseases, National Institutes of Health, testifies during a U.S. Senate Senate Health, Education, Labor, and Pensions Committee Hearing to examine COVID-19, focusing on an update on the federal response at the U.S. Capitol Washington, D.C., U.S., September 23, 2020. Graeme Jennings/Pool via REUTERS

Anthony Fauci, MD, Director, National Institute of Allergy and Infectious Diseases, National Institutes of Health, testifies during a U.S. Senate Senate Health, Education, Labor, and Pensions Committee Hearing to examine COVID-19, focusing on an update on the federal response at the U.S. Capitol Washington, D.C., U.S., September 23, 2020. Graeme Jennings/Pool via REUTERS

Anthony Fauci, MD, Director, National Institute of Allergy and Infectious Diseases, National Institutes of Health, arrives at a U.S. Senate Senate Health, Education, Labor, and Pensions Committee Hearing to examine COVID-19, focusing on an update on the federal response at the U.S. Capitol Washington, D.C., U.S., September 23, 2020. Graeme Jennings/Pool via REUTERS

Anthony Fauci, MD, Director, National Institute of Allergy and Infectious Diseases, National Institutes of Health, looks on before testifying at a U.S. Senate Senate Health, Education, Labor, and Pensions Committee Hearing to examine COVID-19, focusing on an update on the federal response at the U.S. Capitol Washington, D.C., U.S., September 23, 2020. Graeme Jennings/Pool via REUTERS

Anthony Fauci, MD, Director, National Institute of Allergy and Infectious Diseases, National Institutes of Health, looks on before testifying at a U.S. Senate Senate Health, Education, Labor, and Pensions Committee Hearing to examine COVID-19, focusing on an update on the federal response at the U.S. Capitol Washington, D.C., U.S., September 23, 2020. Graeme Jennings/Pool via REUTERS

Anthony Fauci, MD, Director, National Institute of Allergy and Infectious Diseases, National Institutes of Health, looks on before testifying at a U.S. Senate Senate Health, Education, Labor, and Pensions Committee Hearing to examine COVID-19, focusing on an update on the federal response at the U.S. Capitol Washington, D.C., U.S., September 23, 2020. Graeme Jennings/Pool via REUTERS

Anthony Fauci, MD, Director, National Institute of Allergy and Infectious Diseases, National Institutes of Health, looks on before testifying at a U.S. Senate Senate Health, Education, Labor, and Pensions Committee Hearing to examine COVID-19, focusing on an update on the federal response at the U.S. Capitol Washington, D.C., U.S., September 23, 2020. Graeme Jennings/Pool via REUTERS

Anthony Fauci, MD, Director, National Institute of Allergy and Infectious Diseases, National Institutes of Health, looks on before testifying at a U.S. Senate Senate Health, Education, Labor, and Pensions Committee Hearing to examine COVID-19, focusing on an update on the federal response at the U.S. Capitol Washington, D.C., U.S., September 23, 2020. Graeme Jennings/Pool via REUTERS

Anthony Fauci, MD, Director, National Institute of Allergy and Infectious Diseases, National Institutes of Health, looks on before testifying at a U.S. Senate Senate Health, Education, Labor, and Pensions Committee Hearing to examine COVID-19, focusing on an update on the federal response at the U.S. Capitol Washington, D.C., U.S., September 23, 2020. Graeme Jennings/Pool via REUTERS

Stephen Hahn, MD, Commissioner Of Food And Drugs, United States Food and Drug Administration testifies during a U.S. Senate Senate Health, Education, Labor, and Pensions Committee Hearing to examine COVID-19, focusing on an update on the federal response at the U.S. Capitol in Washington, D.C., U.S., September 23, 2020. Alex Edelman/Pool via REUTERS

Stephen Hahn, MD, Commissioner Of Food And Drugs, United States Food and Drug Administration testifies during a U.S. Senate Senate Health, Education, Labor, and Pensions Committee Hearing to examine COVID-19, focusing on an update on the federal response at the U.S. Capitol in Washington, D.C., U.S., September 23, 2020. Alex Edelman/Pool via REUTERS

Stephen Hahn, MD, Commissioner Of Food And Drugs, United States Food and Drug Administration testifies during a U.S. Senate Senate Health, Education, Labor, and Pensions Committee Hearing to examine COVID-19, focusing on an update on the federal response at the U.S. Capitol in Washington, D.C., U.S., September 23, 2020. Alex Edelman/Pool via REUTERS

ADM Brett Giroir, MD, Assistant Secretary For Health, United States Department of Health and Human Services, testifies during a U.S. Senate Senate Health, Education, Labor, and Pensions Committee Hearing to examine COVID-19, focusing on an update on the federal response at the U.S. Capitol in Washington, D.C., U.S., September 23, 2020. Alex Edelman/Pool via REUTERS

Robert Redfield, MD, Director, United States Centers for Disease Control and Prevention, testifies during a U.S. Senate Senate Health, Education, Labor, and Pensions Committee Hearing to examine COVID-19, focusing on an update on the federal response at the U.S. Capitol in Washington, D.C., U.S., September 23, 2020. Alex Edelman/Pool via REUTERS

Robert Redfield, MD, Director, United States Centers for Disease Control and Prevention, testifies during a U.S. Senate Senate Health, Education, Labor, and Pensions Committee Hearing to examine COVID-19, focusing on an update on the federal response at the U.S. Capitol in Washington, D.C., U.S., September 23, 2020. Alex Edelman/Pool via REUTERS

Robert Redfield, MD, Director, United States Centers for Disease Control and Prevention, testifies during a U.S. Senate Senate Health, Education, Labor, and Pensions Committee Hearing to examine COVID-19, focusing on an update on the federal response at the U.S. Capitol in Washington, D.C., U.S., September 23, 2020. Alex Edelman/Pool via REUTERS

Robert Redfield, MD, Director, United States Centers for Disease Control and Prevention, testifies during a U.S. Senate Senate Health, Education, Labor, and Pensions Committee Hearing to examine COVID-19, focusing on an update on the federal response at the U.S. Capitol in Washington, D.C., U.S., September 23, 2020. Alex Edelman/Pool via REUTERS

Anthony Fauci, MD, Director, National Institute of Allergy and Infectious Diseases, National Institutes of Health, testifies during a U.S. Senate Senate Health, Education, Labor, and Pensions Committee Hearing to examine COVID-19, focusing on an update on the federal response at the U.S. Capitol Washington, D.C., U.S., September 23, 2020. Alex Edelman/Pool via REUTERS

Anthony Fauci, MD, Director, National Institute of Allergy and Infectious Diseases, National Institutes of Health, testifies during a U.S. Senate Senate Health, Education, Labor, and Pensions Committee Hearing to examine COVID-19, focusing on an update on the federal response at the U.S. Capitol Washington, D.C., U.S., September 23, 2020. Alex Edelman/Pool via REUTERS

Anthony Fauci, MD, Director, National Institute of Allergy and Infectious Diseases, National Institutes of Health, testifies during a U.S. Senate Senate Health, Education, Labor, and Pensions Committee Hearing to examine COVID-19, focusing on an update on the federal response at the U.S. Capitol Washington, D.C., U.S., September 23, 2020. Alex Edelman/Pool via REUTERS

Anthony Fauci, MD, Director, National Institute of Allergy and Infectious Diseases, National Institutes of Health, testifies during a U.S. Senate Senate Health, Education, Labor, and Pensions Committee Hearing to examine COVID-19, focusing on an update on the federal response at the U.S. Capitol Washington, D.C., U.S., September 23, 2020. Alex Edelman/Pool via REUTERS

Anthony Fauci, MD, Director, National Institute of Allergy and Infectious Diseases, National Institutes of Health, removes his mask as he testifies during a U.S. Senate Senate Health, Education, Labor, and Pensions Committee Hearing to examine COVID-19, focusing on an update on the federal response at the U.S. Capitol Washington, D.C., U.S., September 23, 2020. Alex Edelman/Pool via REUTERS