Influenza kills on average about 20,000 persons annually (range 3,300 to 48,600) in the United States, infecting an estimated 5-20% of the population each year. In addition, influenza viruses can mutate and cause global pandemics, the most recent in 2009. EVC scientists are involved in basic research to try to understand influenza pathogenesis and immune responses needed to protect against the virus.
In addition, EVC investigators are involved in a variety of epidemiologic studies to understand the impact of influenza during pregnancy and the role of vaccines in averting that burden. The principal focus of influenza research at the EVC is through the Influenza Pathogenesis and Immunology Research Center (IPIRC). IPIRC is one of five Centers of Excellence for Influenza Research and Surveillance (CEIRS) designated by the National Institute of Allergy and Infectious Diseases (NIAID) of the National Institutes of Health (NIH), with faculty including multiple EVC members and collaborators. The CEIRS network was designed to lay the groundwork for new and improved control measures for influenza viruses and to expand the NIAID surveillance program both internationally and in the United States. As part of the CEIRS network, IPIRC’s scope includes planning for pandemic influenza and sharing data with other scientists to promote collaboration on new and improved methods to reduce the health burden of influenza viruses. Research is focused on determining how influenza causes disease; how the human immune system responds; the prevalence of avian influenza in animals; how influenza viruses evolve, adapt, and are transmitted; and immunological factors that determine the course of the disease.
IPIRC encompasses researchers from a number of schools and centers at Emory and the University of Georgia, with access to a variety of laboratory and clinical resources. One of the major reasons influenza can cause annual seasonal epidemics and global pandemics is that the virus can mutate and thus evade host immune responses made against prior viruses. Scientists at the EVC and their collaborators have detected a part of the virus that does not mutate and against which an immune response is protective, setting up the possibility of developing an influenza vaccine that can protect against all viruses in the future, thus potentially averting the need for annual vaccination against new strains. Other major breakthroughs include enhancing our understanding, through systems biology, of those genes, when turned on correlate with optimal immune responses and those genes that appear to impede the immune response. This offers the opportunity to design vaccines that include components to turn on or off genes to enhance protection against disease. Work by EVC scientists has documented in animal models that natural host immune responses focus on first viruses seen of a given type which inhibit responses to mutated viruses of that type (Original Antigenic Sin (OAS)). They are working on ways to overcome OAS. Epidemiologists at the EVC have shown that influenza during pregnancy is associated with birth of premature and low birth weight infants. Influenza vaccination during pregnancy leads to decreases in prematurity during periods of high influenza virus circulation, supporting current recommendations for annual vaccination of all pregnant women.