Pioneering Molecular Virologist Flossie Wong-Staal Dies

The University of California, San Diego, researcher helped identify the HIV retrovirus responsible for AIDS and developed treatments still in use today.

Amanda Heidt
Amanda Heidt
Jul 14, 2020
University of california, san diego

Flossie Wong-Staal, a molecular virologist most famous for co-discovering and first cloning the human immunodeficiency virus (HIV) that causes AIDS, died July 8 of complications from pneumonia in La Jolla, California, at age 73.

Wong-Staal arrived at the National Cancer Institute (NCI) in 1973 as a postdoctoral researcher in the lab of fellow virologist Robert Gallo, where she quickly became an essential contributor to the team’s work studying retroviruses. Together, Gallo and Wong-Staal published more than 100 papers in 20 years, according to an article by the NCI, and a 1990 article in The Scientist credits her as being the most-cited woman in science during the 1980s, earning 7,772 citations in academic journals. Wong-Staal was inducted into the National Women’s Hall of Fame last year for her contributions to the field.

“Flossie was one of the best scientists I ever worked with. Without her, loads of stuff in our lab would never have gotten done in the way they happened or with the same speed,” Gallo tells The San Diego Union-Tribune. “She was outstanding, and I will never forget her.” 

During her time in Gallo’s lab, Wong-Staal was part of the group that identified the first human retrovirus, human T-cell leukemia virus type 1 (HTLV-1), and showed that it could cause cancer. While it was already known that retroviruses replicated by inserting their genetic material directly into the genome of their hosts, scientists of the day were skeptical that these viruses could cause cancer in humans. “At the time, the dogma was that [human tumor viruses] did not exist,” Wong-Staal said in a 1997 oral history, adding that the lab was often criticized in its search for “rumor viruses.”  

In the early 1980s, when AIDS cases first began appearing in alarming numbers, Wong-Staal was uniquely poised to study the emerging epidemic—HIV, the virus that causes the disease, turned out to be a retrovirus. A team led by Gallo shared the co-discovery of HIV with the French scientist Luc Montagnier, and Wong-Staal provided the molecular evidence needed as proof. In 1985, she would become the first person to clone HIV and begin studying the functions of its genes, a necessary step towards developing eventual treatments. 

“To have in hand a pure copy of the genetic information of that virus was a critical first step in understanding the molecular biology,” Beatrice Hahn, a molecular virologist at the University of Pennsylvania who previously worked under Wong-Staal, tells The Washington Post.

It was the promise of developing treatments for the disease that finally drew Wong-Staal away from the NCI in 1990, when she joined UC San Diego to launch the new Center for AIDS Research. Under her leadership, the center would emerge as one of the world’s authorities in the field. The drug cocktails used today to manage AIDS stem from Wong-Staal’s studies of the variations in the virus’s genetic material. Later, with her second husband Jeffrey McKelvy, she co-founded a biopharmaceutical company called Immusol (later renamed iTherX Pharmaceuticals) to continue developing therapies for diseases such as hepatitis C.

While Wong-Staal had retired by the time of her death, she continued pursuing certain passion projects, including her work at iTherX. It was this dedication to her work that earned the admiration of her colleagues, her family recalls. “I have this memory of her in a lab coat surrounded by men, all who were much taller. She was only 5 foot 2. But she always had a commanding presence,” her daughter, Caroline Vega, tells The Union-Tribune.  

Wong-Staal is survived by her husband, two daughters, a sister, two brothers, and four grandchildren.