The CARES Act requires GAO to look at the government's response to the COVID-19 pandemic, including vaccine development. Vaccines prepare the body to respond quickly to an infection and play a key role in keeping people and global communities healthy. Overall, vaccine development is still difficult, complex, and costly. But we identified 16 innovative technologies and approaches that may enhance the nation's ability to respond to high-priority infectious diseases. Some innovative technologies—like reverse vaccinology that uses computers to analyze the genetics of a pathogen—helped researchers develop COVID-19 vaccines quickly and effectively.