PLANNING TOOLS FOR PREPARATION AND RESPONSE At the onset of an outbreak with pandemic potential, the uncertainty and complexity of the situation demand ways to assess the risk and potential public health impact posed by the emerging virus, understand the possible progression of the event, and evaluate its severity and transmissibility to enable informed public health interventions. HHS has developed and refined three tools over the past decade to help guide different aspects of planning and response: the Pandemic Intervals Framework (PIF), the Influenza Risk Assessment Tool (IRAT), and the Pandemic Severity Assessment Framework (PSAF). Details about these tools are included in Appendix B. These tools align with the WHO initiative for all nations to develop response plans within the WHO’s global framework of pandemic phases and risk-assessment activities for preparedness, response, and recovery. The PIF defines and describes six time intervals of an influenza pandemic, including indicators signaling each interval and recommended interventions. There are two pre- pandemic intervals, investigation and recognition, and four pandemic intervals that include initiation, acceleration, deceleration, and preparation. The PSAF is a systematic framework for assessing the public health effects of an emerging pandemic. It helps to identify the type and timing of actions needed for effective intervention, thus informing the development of operational plans and guiding response efforts. The IRAT assesses the potential human pandemic risk of novel influenza A viruses to inform decisions regarding the development, manufacturing, use, and stockpiling of diagnostics, vaccines, and therapeutics. The IRAT process is continual among HHS pandemic influenza stakeholders to monitor for, and assess when, a novel influenza A virus in animals or humans has been identified. Experts assess the potential for emergence and human health risk of the virus to anticipate the risk that the virus will 1) develop efficient and sustained human-to-human transmission (emergence), and 2) significantly affect public health (impact). The IRAT and PSAF are complementary tools. Should widespread human disease occur, the PSAF is the companion tool for estimating a pandemic’s potential impact; the PSAF uses two sets of measures to score viral transmissibility and clinical severity of new influenza A viruses as they circulate among humans. 12