When the flu follows you, you follow the flu.
By Susan Kirtz, MPH
Managing Editor, Texas Health Journal
Director of Special Projects, Center for Health Communication
The University of Texas at Austin
In 2009, Spencer Fox woke up with a fever, chills, muscle aches, cough, and a runny nose. A test from his doctor confirmed that he, like many others that spring, had the flu. Fox was part of the 2009 H1N1 “swine flu” pandemic. A pandemic that, according to the Centers for Disease Control and Prevention (CDC), infected 60.8 million people and resulted in 12,469 deaths in the United States from April 2009 to 2010.
Media coverage of the outbreak was immense, piquing the interest of the public and of scientists around the world, including Fox, who was an undergraduate student in biology at the time. Now a PhD student in the Ecology, Evolution, and Behavior graduate program at the University of Texas at Austin, Fox has already started making a career in the study of infectious diseases like influenza. Working with his advisor, Dr. Lauren Ancel Meyers, a Professor of Integrative Biology in the College of Natural Sciences, Fox focuses on statistical modeling of infectious disease dynamics.
He began his graduate studies with Dr. Meyers the year that the CDC launched their “Predict the Influenza Season Challenge.” Participants were asked to forecast the timing, peak and intensity of the 2013-2014 flu season using digital data, and Fox led the UT Austin team in submitting their predictions. They didn’t win, but Fox describes it as a great experience to kick off his first year in Dr. Meyers’s lab. It also helped cement his interest in the flu.
In a recent study, “Seasonality in Risk of Pandemic Influenza Emergence,” Fox returned to the idea of pandemics, and started thinking about that unusually timed spring flu he had in 2009. The CDC defines an influenza pandemic as a “global outbreak of a new influenza A virus that is very different from current and recently circulating human seasonal influenza A viruses.” In reviewing historical flu surveillance data, Fox noticed that in contrast to the regular fall and winter flu season, the six pandemics on record (1889, 1918, 1957, 1968, 1977, and 2009) all occurred in the spring and summer months. What could explain that pattern?
The results of research by Fox and his colleagues suggest that seasonal flu epidemics result in a brief “refractory period” of immunity that impedes the emergence of a pandemic. “There seems to be a growing body of evidence that when someone gets infected with the flu, they develop short-term general immunity that protects them against all different types of flu,” says Fox. This refractory period explains the spring and summer timing of flu pandemics, like the one Fox experienced in 2009. The pandemics emerge after the general immunity from the seasonal flu attenuates.
Fox explained that, although more work is needed to understand short-term immunity, the research he and his colleagues have done indicates that public health surveillance agencies like the CDC can use regional flu epidemic data to understand a population’s risk of experiencing a pandemic. This insight may help guide local, national, and world public health leaders in determining where and when to focus prevention efforts.
Fox and Dr. Meyers haven’t finished following the flu. They intend to pursue future studies to quantify the magnitude and duration of this short-term, generalized immunity. How long does it last? Does it prevent people from getting sick, or does it just prevent people from transmitting the flu to others? Fox’s plans for after graduation are wide open, but wherever he goes his research will continue to change the way that we understand infectious diseases like the flu.