The Quiet Expert Who Stood Between Us and a Flu Pandemic
Most Americans haven’t heard of Nancy Cox, but we’ve all been touched by her work
The only thing predictable about influenza is that it’s unpredictable.
It’s a simple, memorable and powerful saying, often repeated by one of the world’s foremost experts in flu.
Dr. Nancy Cox died last week at 77, of brain cancer. For more than two decades, she ran the influenza division at the Centers for Disease Control and Prevention. Most Americans have never heard her name, but her work prevented catastrophes the rest of us never had to think about.
I worked with Dr. Cox during my years as CDC director. She was impressive and intimidating. Impressive, because she knew more about flu than anyone—the virology, the epidemiology, the history, the process of vaccine strain selection, the names of laboratory directors and experts in dozens of countries, and much, much more. Intimidating, because in any room where the conversation turned to flu, she clearly knew so much that it was hard to keep up.
When Dr. Cox took over the CDC influenza division in 1992, it had 14 staff. By the time she retired in 2014, it was a powerhouse unit and was anchored to a worldwide network of laboratories that, every year, characterizes thousands of viruses to update the flu vaccine. Hundreds of millions of people worldwide benefit from this work. It’s painstaking, methodical, and largely unseen. It’s also what stands between us and the next pandemic.
Lasting accomplishments
Dr. Cox leaves a deep legacy that will carry on in communities and countries around the world. Some examples:
A global flu surveillance network. Dr. Cox helped strengthen the WHO Global Influenza Surveillance and Response System—a worldwide network of flu laboratories that detect and characterize new strains in real time. This is the foundation that lets the world choose the best possible vaccine for each season and spot pandemic threats early.
The seed viruses behind flu shots. Wild flu virus from a patient doesn’t grow well enough in chicken eggs to make vaccine at scale. Dr. Cox’s lab refined the reassortment techniques—pairing each year’s circulating strain with a high-yield workhorse virus first isolated in 1934—that allow manufacturers to produce hundreds of millions of doses on time.
A pandemic head start. CDC’s library of candidate vaccine viruses against H5N1, H7N9, and other potential pandemic strains, built and maintained under her leadership, gives manufacturers a running start when a pandemic strikes.
Tools used to judge a pandemic threat. Dr. Cox led development of the Influenza Risk Assessment Tool, which helps evaluate whether a new flu virus could become a pandemic. She also helped develop the Pandemic Severity Assessment Framework and the federal Pandemic Intervals Framework. WHO adapted her tool into its own global version. Officials rely on these tools to decide what to stockpile and how to respond.
Mortality estimates to drive policy. She was co-author of a foundational JAMA study that provided estimates of U.S. influenza-associated deaths and hospitalizations, a crucial source for vaccination recommendations.
A generation of public health scientists. Dr. Cox trained, mentored, and championed scientists who now lead flu surveillance and response across the United States and around the world.
In April 2009, just before I arrived as CDC director, a novel H1N1 virus emerged in Mexico and California. Dr. Cox and her team identified the virus, characterized it, and shared it with the world within days. Within two weeks, CDC distributed more than a million test kits to all 50 states and 140 countries. Compare that with the catastrophic CDC test failure at the start of Covid . The difference was decades of investment in the people, laboratories, and relationships Dr. Cox built.
That same spring in 2009, lightning struck Dr. Cox’s house and burned it to the ground. No one was hurt. She returned to the office the next day in clothes that smelled of smoke. “I flipped a switch in my mind,” she said later, “to concentrate on what we thought might turn into a pandemic.”
In 2006, the Partnership for Public Service named Dr. Cox a Federal Employee of the Year through its “Sammies”—the Samuel J. Heyman Service to America Medals, the closest thing the federal civil service has to an Oscar. Time put her on its 100 Most Influential People list the same year. Dr. Cox was the kind of public servant Michael Lewis profiles in Who Is Government?—federal civil servants whose names most Americans never hear but whose work is invaluable.
No single country can see a flu pandemic coming. Influenza begins in animals, jumps to humans, and travels around the world in days. To detect a new strain early, scientists in Beijing, Memphis, Melbourne, Cairo, and Atlanta must share samples and sequence data in real time. Dr. Cox built those relationships over years—through visits, training, and co-authorships.
The kind of trust that Dr. Cox fostered takes decades to build. It can be lost much faster. Cuts have gutted CDC. Global surveillance funding is gone. Laboratories in countries where pandemics begin no longer have American partners. WHO’s ability to coordinate global virus tracking has been disrupted. H5N1 keeps spreading in dairy cattle and other animals in the United States, and we know less about it than we should. Last year, after the virus jumped into dairy herds, Dr. Cox told STAT the virus must have “some kind of special sauce”—her dry phrase for a pathogen that keeps rewriting the textbook.
Influenza is predictably unpredictable. We are safer because of what Dr. Cox and others built. It’s also predictable that we will be less safe if we let it go.