De facto standard = the gold standard treatment of influenza and presumably covid-19

https://www.cdc.gov/flu/professionals/diagnosis/overview-testing-methods.htm

Key to stopping covid = stopping the cytokine storm at the start

The CDC’s de facto standard in treating influenza - baloxavir marboxil

Approved by the FDA in Oct 2018

https://www.cdc.gov/flu/treatment/baloxavir-marboxil.htm#anchor_1544111937894