Pandemic Preparedness and the Influenza Risk Assessment Tool (IRAT)

Influenza infections have resulted in millions of deaths and untold millions of illnesses throughout history. Influenza vaccines are the cornerstone of influenza prevention and control. Recommendations are made by the World Health Organization (WHO) 6-9 months in advance of the influenza season regarding what changes, if any, should be made in the formulation of seasonal influenza vaccines. This allows time to manufacture, test, distribute, and administer vaccine prior to the beginning of the influenza season. At the same time experts also consider which viruses not currently circulating in the human population, but with pandemic potential, pose the greatest risk to public health. Experts may conclude that one or more of these viruses are of enough concern to warrant development of a high-growth reassortant candidate vaccine virus. Subsequently, national authorities may determine that a vaccine should be manufactured, tested in clinical trials, and even stockpiled in some circumstances. The Influenza Risk Assessment Tool (IRAT) was created in an effort to develop a standardized set of elements that could be applied for decision making when evaluating pre-pandemic viruses. The tool is a simple, additive model, based on multi-attribute decision analysis. The ultimate goal is to identify an appropriate candidate vaccine virus and prepare a human vaccine before the virus adapts to infect and efficiently transmit in susceptible human populations. This pre-pandemic preparation allows production of vaccine-a strategy that could save lives and mitigate illness during a pandemic.