David Aaron Kessler (born May 13, 1951) is an American pediatrician, attorney, author, and administrator (both academic and governmental) serving as Chief Science Officer of the White House COVID-19 Response Team since 2021. Kessler was the commissioner of the Food and Drug Administration (FDA) from November 8, 1990, to February 28, 1997. He co-chaired the Biden-Harris transition’s COVID-19 Advisory Board from November 2020 to January 2021 and was the head of Operation Warp Speed, the U.S. government program to accelerate the development of COVID-19 vaccines and other treatments, from January to February 2021. Background After graduation from Amherst College in 1973, Kessler studied medicine at Harvard University, obtaining an M.D. degree in 1979. While at Harvard, Kessler obtained a J.D. degree in 1977 from the University of Chicago Law School. While serving his residency in pediatrics at Johns Hopkins Hospital in Baltimore, he worked as a consultant to Republican senator Orrin Hatch from Utah, particularly on issues relating to the safety of food additives, and on the regulation of cigarettes and tobacco. From 1984 to 1990, Kessler simultaneously ran a 431-bed teaching hospital in New York City and taught at the Columbia Law School and the Albert Einstein College of Medicine. As FDA commissioner Although his appointment as FDA commissioner in 1990 by President George H. W. Bush won bipartisan approval, many of Kessler's actions were controversial, and he soon became more popular with Democrats than Republicans. He moved quickly to make the agency more efficient, reducing the time needed to approve or reject new drugs, including AIDS drugs, and more vigilant in protecting consumers against unsafe products and inflated label claims. It was also on his watch that FDA enacted regulations requiring standardized Nutrition Facts labels on food. In one memorable action, he had 24,000 gallons of Citrus Hill orange juice seized because, although made from concentrate, it was labeled "fresh." Kessler was reappointed to the post of FDA Commissioner during the administration of Bill Clinton. Kessler is also known for his role in the FDA attempt to regulate cigarettes, which resulted in the FDA v. Brown & Williamson Tobacco Corp. case. The Supreme Court ultimately ruled that the FDA did not have the power to enact and enforce the regulations in question. He was awarded the Public Health Hero award on April 2, 2008, by the UC Berkeley School of Public Health for his work in tobacco regulation.