Influenza

• Influenza, also known as the flu, is a contagious illness caused by influenza viruses that are spread through respiratory droplets.
• Adults experience mild to severe symptoms while seniors, children and patients with compromised immune systems are at risk for more serious and even life-threatening infection. Symptoms may include fever, cough, runny nose, muscle or body aches and fatigue.
  
• Influenza viruses are primarily classified as Type A or B. Type B viruses are identified by their strain, while Type A viruses are divided into subtypes based on two proteins on the surface of the virus: hemagglutinin (H) and the neuraminidase (N).
  
• Influenza can be prevented by receiving a vaccine that is administered as either a shot or nasal-spray. Vaccines are developed each season to protect against the three Influenza viruses that researchers predict will be the most common during the season. Influenza infections are treated using antivirals, the most common of which is oseltamivir, known as Tamiflu.

Drug resistance - Center researchers used computer modeling to determine that the rapid spread of a Tamiflu-resistant strain of influenza A (H1N1) between 2006 and 2009 was likely due to a genetic mutation that increased transmissibility and not because of widespread over-prescription of Tamiflu. Learn more »

Pandemic planning - An outbreak of pandemic influenza in the United States could be mitigated with prompt implementation of social-distancing measures - such as school closures - combined with antiviral treatment and preventative medicine until a vaccine is available, according to findings by Center researchers. The analysis, led by Dr. Elizabeth (Betz) Halloran, was a coordinated effort by leading mathematical modeling centers. The research was part of a larger effort to guide national pandemic response planning. Learn more »

The design and analysis of vaccine studies - Researchers at the Center design and analyze data from vaccine trials. Dr. Halloran’s research group collaborates with the Program for Appropriate Technology in Health (PATH) on the design and analysis of the first trial of the effectiveness of influenza vaccine among children in rural Senegal, Africa. In addition to the analysis of actual trial data, Dr. Halloran remains a leading expert on the development of novel statistical approaches for estimating the efficacy and effectiveness of vaccines in field studies. Mathematical modeling efforts at the Center, led by Dr. Halloran, use these efficacy estimates to project the effectiveness of large-scale influenza vaccination campaigns. Under Dr. Halloran’s leadership, researchers have also estimated the efficacy of several non-pharmaceutical interventions against influenza (for example, the use of alcohol-based hand sanitizers in schools), most notably in collaboration with the Pittsburg Influenza Prevention Project.

Analysis of outbreak of novel influenza variants - In support of pandemic planning for influenza, Center researchers provide analytic support for field investigations of the outbreaks of novel influenza variants. Researchers, led by Dr. Halloran, have provided support to investigators at the Centers for Disease Control and Prevention (CDC), the Los Angeles County Department of Public Health, and Seattle & King County Public Health. Analyses conducted as part of these collaborations have led to an increased understanding of the dynamics of influenza transmission during the very early phases of the pandemic. Dr. Halloran’s research group is currently working with the CDC to analyze data related to the ongoing emergence of a novel swine variant of the influenza A H3N2 subtype. To be more proactive in preparing for future outbreaks of novel influenza variants, Dr. Halloran’s group recently obtained funding to support the development of novel statistical methods for the analysis outbreak investigation data, including real-time analytics support for prevention and control efforts.