Several potential treatments for COVID-19, including oral antivirals, are undergoing various stages of development and study as global demand is competitive. Access to effective treatments for infected individuals could reduce the severity of COVID-19 for individuals and reduce the strain on the health care system.
As you said, the supplementary estimates (C) include new funding of $1 billion to serve as a contingency fund that may be used for the purchase of additional treatments. More specifically, procurement of pharmaceutical products in short supply, such as Paxlovid, is done by the Government of Canada under the authority of the Minister of Health, and treatments procured will support provincial and territorial health care systems as well.