OpenAI employees have been granted a total of $80bn. If employees are exceptionally generous, perhaps they give a total of 10% of that--a one-off windfall of $8bn.
In 2023, USAID had an annual budget of $43bn.
https://www.nytimes.com/2026/10/20/us/politics/ai-fortunes-could-bring-critical-funds-to-global-health-the-scramble-is-on.html