remain available until September 30, 2024, to prevent, prepare for, and respond to coronavirus, domestically or internationally, including the development of necessary countermeasures and vaccines, prioritizing platform-based technologies with U.S.-based manufacturing capabilities, the purchase of vaccines, therapeutics, diagnostics, and necessary medical supplies, as well as medical surge capacity, workforce modernization, enhancements to the U.S. Commissioned Corps, telehealth access and infrastructure, initial advanced manufacturing, and related administrative activities: Provided , That no less than $1,000,000,000 shall be dedicated to the development, translation and demonstration at scale of innovations in manufacturing platforms to support vitally necessary medical countermeasures to support a reliable U.S.-sourced supply chain of: (a) vaccines, (b) therapeutics, (c) small molecule APIs (active pharmaceutical ingredients), including construction costs: Provided further , That the Secretary of Health and Human Services shall purchase vaccines developed using funds made available under this heading in this Act to respond to an outbreak or pandemic related to coronavirus in quantities determined by the Secretary to be adequate to address the public health need: Provided further , That products purchased by the Federal government with funds made available under this heading, including vaccines, therapeutics, and diagnostics, shall be purchased in accordance with Federal Acquisition Regulation guidance on fair and reasonable pricing: Provided further , That the Secretary may take such measures authorized under current law to ensure that vaccines, therapeutics, and diagnostics developed from funds provided in this Act will be affordable in the commercial market Provided further , That in carrying out the preceding proviso, the Secretary shall not take actions that delay the development of such products: Provided further, That products purchased with funds appropriated in this paragraph may, at the discretion of