The following description was taken from Public Health Emergency: Contracts

The HHS Office of the Assistant Secretary for Preparedness and Response (ASPR) uses an integrated, systematic approach to the development and purchase of the necessary vaccines, drugs, therapies, and diagnostic tools for public health medical emergencies. These include advanced development of medical countermeasures to natural and intentional threats to public health and the commodities and services need to support the public health response to and recovery from domestic and international public health and medical threats and emergencies.