Infectious diseases continue to emerge and spread into new regions in the setting of globalization and environmental change. Understanding these dynamics and increasing global capacity for preparedness and response is crucial for mitigating future pandemics. This chapter highlights key frameworks for understanding pathogen spillover and emergence, from the lenses of One Health, planetary health, and health security. Additionally, this chapter summarizes all phases of the public health emergency management cycle in the context of pandemics (prevention, preparedness, event detection, risk assessment, response, and recovery). Examples are given for novel developments in each of these phases, as well as areas for future action. Overall, while there have been tremendous advancements since the COVID-19 pandemic (improved diagnostics and novel therapeutics/vaccines), there are ongoing gaps in health equity and multisectoral coordination, which may be worsened by the climate crisis and global change.