The Influenza and Other Viruses in the Acutely Ill (IVY) Network is a collaboration of research groups from 21 academic medical centers in the United States (US) and the Centers for Disease Control and Prevention (CDC) and is coordinated from Vanderbilt University Medical Center. The IVY Network studies the epidemiology of severe illness caused by respiratory viruses among adults in the US and the effectiveness of vaccines to prevent those illnesses. Formed in 2019, the IVY Network has enrolled over 15,000 participants into observational research studies and public health surveillance projects. Among their work includes one of the first descriptions of Long COVID syndrome, data demonstrating different effectiveness among COVID-19 vaccines being used in the US, and the effectiveness of COVID-19 mRNA vaccines for attenuating illness severity among adults who develop COVID-19 despite vaccination. The IVY Network has published dozens of original research manuscripts, including in the Journal of the American Medical Association (JAMA), Morbidity and Mortality Weekly Report (MMWR), and Clinical Infectious Diseases (CID), among many other journals. The IVY Network continues to study COVID-19 and is also studying influenza and respiratory syncytial virus (RSV).

The overarching goal of the IVY Network is to improve human health by enhancing our biological understanding of severe respiratory infections and providing evidence to support data-driven public health policy.