Purnell W. Choppin, MD, a pioneering virologist who helped transform HHMI into one of the largest scientific and philanthropic organizations in the world, died July 3, 2021.

Purnell W. Choppin, who served as president of the Howard Hughes Medical Institute from 1987 to 1999, died July 3, 2021. Credit: Paul Fetters

Purnell W. Choppin, MD, a pioneering virologist who helped transform the Howard Hughes Medical Institute (HHMI) into one of the largest scientific and philanthropic organizations in the world, died July 3. He was 91.

Choppin came to HHMI in 1985 as vice president and chief scientific officer and served as president from 1987 to 1999. The year Choppin arrived, HHMI sold a principal asset, Hughes Aircraft, generating an endowment of $5.2 billion and instantly making the Institute the largest scientific philanthropy in the world at the time. Choppin guided HHMI through a period of remarkable expansion – more than tripling the number of HHMI Investigators, launching a grants program in science education, and building a new headquarters in Chevy Chase, Maryland, among other endeavors.

Choppin realized that most scientists lack sufficient funds to pursue highly innovative ideas. Rather than providing individual grants for specific projects, HHMI centered its philanthropy on identifying and employing innovative biomedical scientists already at research institutions and providing them with generous, largely unrestricted budgets for research, with periodic review for continuing support. He coined the phrase “people, not projects” to describe HHMI’s approach.

“It really was very exciting to suddenly have the resources to support the best people we could find, wherever they were,” Choppin said in a 2013 interview. “We don’t have to uproot people. I mean the amount of investment we can make, the fact that we can support people wherever they are…that’s unusual.”

Former HHMI Board of Trustees Chair Hanna H. Gray, who participated in the selection of Choppin as president, described him as “the obvious choice” for that role based on his research accomplishments, strong reputation in the scientific community, and knowledge of HHMI as chief scientific officer. Gray credits Choppin with steering “an immensely productive era” for HHMI: “At a crucial time in HHMI’s evolution, Purnell’s selfless leadership guided the Institute in defining and successfully securing the essential scientific and philanthropic priorities to which HHMI is dedicated. In addition, his personal qualities of deep integrity, fair-mindedness, patience, and decency helped hold the Institute to a steady path.”

“It really was very exciting to suddenly have the resources to support the best people we could find, wherever they were.”

Purnell Choppin, former HHMI President

Current HHMI President Erin O’Shea, who became an Investigator in 2000 and HHMI president in 2016, notes that during Choppin’s time as president, HHMI became known for catalyzing scientific discovery in fields such as structural biology. For decades, research methods to peer deeply inside cells were so obscure, expensive, and elaborate that very few scientists could hope to do so. Under Choppin’s leadership, HHMI invested in basic research that ultimately contributed to high-powered X-ray beamlines, innovations in microscopy, scores of protein structures, answers to long-standing questions in biology, and multiple Nobel Prizes.

“As a biochemist, I benefited from the science coming out of HHMI labs, and I was really eager to join this community of scholars,” says O’Shea. “Since becoming president, I’ve come to deeply appreciate all that Purnell made possible for the Institute and for generations of scientists to come. HHMI would not be what it is today without him.”

Over the course of Choppin’s career, he received many awards, including the Howard Taylor Ricketts Award from the University of Chicago and the Selman A. Waksman Award in Microbiology from the National Academy of Sciences. He was a member of the National Academy of Sciences, the National Academy of Medicine, the American Philosophical Society, and the American Academy of Arts and Sciences.

Choppin came to HHMI from the Rockefeller University, where he served on the faculty for 28 years. From the late 1950s to the mid-1980s, Choppin and his colleagues in the Laboratory of Virology studied how viral particles, particularly those responsible for influenza and measles, attach to cells, inject them with viral proteins and RNA, and turn them into factories for manufacturing additional virus particles. In addition to explaining how viruses infect and sicken us, investigations in Choppin’s lab shed light on other medically important topics such as tumor formation and illuminated fundamental aspects of cell biology and gene function.

Toward the end of his tenure at Rockefeller, Choppin and his team helped explain how persistent viral infections can lead to chronic neurological disease, and they used their knowledge of viral proteins to develop antiviral agents that successfully inhibited infection by influenza viruses.

Choppin also was an institutional leader at Rockefeller, serving as vice president for academic programs and as dean of the graduate school. Rockefeller University President Richard Lifton, himself a former HHMI Investigator, notes: “I suspect all who knew Purnell found his perennial good-natured optimism, generosity, curiosity, scholarship, insistence on excellence, and integrity to be defining qualities that made him such an inspiring person.”


HHMI is the largest private biomedical research institution in the nation. Our scientists make discoveries that advance human health and our fundamental understanding of biology. We also invest in transforming science education into a creative, inclusive endeavor that reflects the excitement of research. HHMI’s headquarters are located in Chevy Chase, Maryland, just outside Washington, DC.

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